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Science Section => Science General Discussion => Topic started by: Solitary on June 11, 2013, 02:02:30 AM

Title: Why Witch Sabrina Looks Thinner While Riding On Her Broom.
Post by: Solitary on June 11, 2013, 02:02:30 AM
:evil:
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on June 11, 2013, 05:43:11 AM
Quote from: "Solitary":wink: If you have a clock and watch a moving clock, that clock will "appear" to you to run slower. This is called time dilation. However, an observer like Which Sabrina flying on her broom with the clock will not notice anything different about her clock, but she will see yours moving more slowly.

The same is true for measured distance between events. A meter long broom like Which Sabrina has is, by definition, a meter long as measured in a referance frame at rest with respect to the broom. If that meter broom is moving across your line-of-sight, you will "observe" it, as well as Witch Sabrina, shrink in the direction of their motion.

This is called Fitzgerald-Lorentz contraction. Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion. These are all "aparent" dilations, not actual, as so many writers claim.  :P  Bill

That's wrong. Get your facts straightened before spewing your ignorance.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: AllPurposeAtheist on June 11, 2013, 08:00:52 AM
Calling Sabrina fat will render you into a newt.. No further action required on your part.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on June 11, 2013, 09:14:38 AM
Quote from: "josephpalazzo"
Quote from: "Solitary":wink: If you have a clock and watch a moving clock, that clock will "appear" to you to run slower. This is called time dilation. However, an observer like Which Sabrina flying on her broom with the clock will not notice anything different about her clock, but she will see yours moving more slowly.

The same is true for measured distance between events. A meter long broom like Which Sabrina has is, by definition, a meter long as measured in a referance frame at rest with respect to the broom. If that meter broom is moving across your line-of-sight, you will "observe" it, as well as Witch Sabrina, shrink in the direction of their motion.

This is called Fitzgerald-Lorentz contraction. Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion. These are all "aparent" dilations, not actual, as so many writers claim.  :P  Bill

That's wrong. Get your facts straightened before spewing your ignorance.

HEY!  If you have Other *facts* to share - you can do so without making this thread ugly.
Thanks Solitary.  Not a single clue what you're talking about - but me on a broom? You bet! Me even thinner? YAY me.
lol
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on June 11, 2013, 09:16:31 AM
She turned me into a newt!
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on June 11, 2013, 09:48:33 AM
Which Sabrina is this "Which Sabrina" you're talking about?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: AllPurposeAtheist on June 11, 2013, 09:56:18 AM
Which which would a which which be if a which which could chuck wood?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on June 11, 2013, 09:59:52 AM
Quote from: "WitchSabrina"
Quote from: "josephpalazzo"
Quote from: "Solitary":wink: If you have a clock and watch a moving clock, that clock will "appear" to you to run slower. This is called time dilation. However, an observer like Which Sabrina flying on her broom with the clock will not notice anything different about her clock, but she will see yours moving more slowly.

The same is true for measured distance between events. A meter long broom like Which Sabrina has is, by definition, a meter long as measured in a referance frame at rest with respect to the broom. If that meter broom is moving across your line-of-sight, you will "observe" it, as well as Witch Sabrina, shrink in the direction of their motion.

This is called Fitzgerald-Lorentz contraction. Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion. These are all "aparent" dilations, not actual, as so many writers claim.  :P  Bill

That's wrong. Get your facts straightened before spewing your ignorance.

HEY!  If you have Other *facts* to share - you can do so without making this thread ugly.
Thanks Solitary.  Not a single clue what you're talking about - but me on a broom? You bet! Me even thinner? YAY me.
lol

I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: AllPurposeAtheist on June 11, 2013, 10:01:41 AM
The moral high ground was dug up and made into a walmart apparently today.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on June 11, 2013, 10:11:59 AM
:evil:
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: AllPurposeAtheist on June 11, 2013, 10:14:06 AM
I thought your post was ok even if I just barely skimmed it and have forgotten all of it already. :)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on June 11, 2013, 10:27:03 AM
Quote from: "josephpalazzo"That's wrong. Get your facts straightened before spewing your ignorance.

Quote from: "josephpalazzo"I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.

You may or may not know a bit about physics, I'm not sure -- but  you clearly don't know shit about people.  If you were concerned with helping clear up their misconceptions, you wouldn't use invective which is certain to rile the students you're trying to educate.  Anyone with half-a-brain knows that insulting one's audience only works in stand-up comedy.  

As a result, your posts strike me as attempts to assuage your own insecurities by treating others contemptuously.  Maybe I'm wrong, and maybe you're a decent person who knows how to communicate respectfully.  But I've yet to see any evidence of that, myself.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: stromboli on June 11, 2013, 10:37:21 AM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"That's wrong. Get your facts straightened before spewing your ignorance.

Quote from: "josephpalazzo"I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.

You may or may not know a bit about physics, I'm not sure -- but  you clearly don't know shit about people.  If you were concerned with helping clear up their misconceptions, you wouldn't use invective which is certain to rile the students you're trying to educate.  Anyone with half-a-brain knows that insulting one's audience only works in stand-up comedy.  

As a result, your posts strike me as attempts to assuage your own insecurities by treating others contemptuously.  Maybe I'm wrong, and maybe you're a decent person who knows how to communicate respectfully.  But I've yet to see any evidence of that, myself.

^this. What you are doing is tantamount to painting yourself into a corner.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on June 11, 2013, 10:52:25 AM
Quote from: "Solitary":oops: He! He! typo, at least I got it right half the time. As to those who think I'm ignorant just because someone thinks so, doesn't make it so. I won't go into who I am, but if anyone that comes here that thinks I'm wrong with my post check it out in any science or math book on the subject and see if I'm wrong---then come back here is show everyone who is ignorant at this thread.  8-)  Solitary AKA Bill

You wrote: "These are all "aparent" dilations, not actual, as so many writers claim."

Tell that to the physicists working in Argentina, where you get the most particles from cosmic radiation. When you calculate the half-life of the cosmic muons, compared to the lab muons, their half-life difference matches exactly what Special Relativity predicts. Time dilation is real, not apparent as you have claimed.


You wrote: "Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion."

No, it doesn't work that way.  You need to know about proper time. To do that you need to know who will measure two events with one clock. Example: you send someone to Alpha Centauri at near the speed of light. The person in the rocketship  will measure the departure and arrival (two events) with the same clock. That's the proper time. The observer on earth will need two clocks, one for the departure on earth, and a second clock on Alpha Centauri to measure the second event, the arrival. For the earth observer that is the improper time. The two times are related by,

T(proper time)  = t(improper time) ( 1 - v[sup:3jzoyzva]2[/sup:3jzoyzva]/c[sup:3jzoyzva]2[/sup:3jzoyzva])[sup:3jzoyzva]-1/2[/sup:3jzoyzva]

Otherwise you get the ridiculous claim: "the guy on the rocketship sees the earth moving so he thinks the people on earth are experiencing time dilation". Noboby "feels" like their experiencing time dilation. It's only when they will compare notes that they will realize that their clock was ticking differently, or that one looks younger than the other. The effect is real, even though the people on the rocketship don't feel it, they will experience time dilation, not the people on earth.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on June 11, 2013, 11:09:23 AM
Quote from: "stromboli"
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"That's wrong. Get your facts straightened before spewing your ignorance.

Quote from: "josephpalazzo"I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.

You may or may not know a bit about physics, I'm not sure -- but  you clearly don't know shit about people.  If you were concerned with helping clear up their misconceptions, you wouldn't use invective which is certain to rile the students you're trying to educate.  Anyone with half-a-brain knows that insulting one's audience only works in stand-up comedy.  

As a result, your posts strike me as attempts to assuage your own insecurities by treating others contemptuously.  Maybe I'm wrong, and maybe you're a decent person who knows how to communicate respectfully.  But I've yet to see any evidence of that, myself.

^this. What you are doing is tantamount to painting yourself into a corner.

You're free to listen to idiots and quacks. I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who  believe in unacceptable religious beliefs, like vaginal mutilation. Do you think we should respect that?! Why?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on June 11, 2013, 11:11:45 AM
Quote from: "josephpalazzo"I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.


Not for nothing but we've had **experts** on this or that come stomping through here before.  And likely we will again.

Now --- there's two ways to go about slinging your expertise around:  There's the asshole method of calling long time members morons (aka thinking Very highly of ones self)  And there's the more respectful, professional method of just sharing your opinions or know-how in the form of adding data to the thread.  That shared data can lead to even more conversations.  Being a forum and all - wow - imagine that? Conversations.   :shock:  :shock:
Sometimes we find out much about a person's character - not by What they know - but rather how they choose to share what they know.

or


you can just become a newly-resident asshole and be known as such.

The choice - of course - is always yours.


Ask anyone here - but I can get fiercely loyal for my friends and how they are treated.   They don't even have to be right 100% of the time.    This IS A FORUM -- aka human interaction-- many of different styles and different methods will post here.  You can BE part of the forum or just be stubborn and nasty towards forum members.
I officially ASK that you consider what I am saying to you - here - Now.
My suggestion?  Back down a notch on shoving your expertise down everyone's throat.  No matter How correct you are - that method never ever works.  Like ever.

cheers
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on June 11, 2013, 11:18:47 AM
Quote from: "josephpalazzo"
Quote from: "Solitary":oops: He! He! typo, at least I got it right half the time. As to those who think I'm ignorant just because someone thinks so, doesn't make it so. I won't go into who I am, but if anyone that comes here that thinks I'm wrong with my post check it out in any science or math book on the subject and see if I'm wrong---then come back here is show everyone who is ignorant at this thread.  8-)  Solitary AKA Bill

You wrote: "These are all "aparent" dilations, not actual, as so many writers claim."

Tell that to the physicists working in Argentina, where you get the most particles from cosmic radiation. When you calculate the half-life of the cosmic muons, compared to the lab muons, their half-life difference matches exactly what Special Relativity predicts. Time dilation is real, not apparent as you have claimed.


You wrote: "Which Sabrina riding on the broom will not notice anthing different about her broom or herself, but will "observe" one at rest in your frame of reference shrink in the direction of its motion."

No, it doesn't work that way.  You need to know about proper time. To do that you need to know who will measure two events with one clock. Example: you send someone to Alpha Centauri at near the speed of light. The person in the rocketship  will measure the departure and arrival (two events) with the same clock. That's the proper time. The observer on earth will need two clocks, one for the departure on earth, and a second clock on Alpha Centauri to measure the second event, the arrival. For the earth observer that is the improper time. The two times are related by,

T(proper time)  = t(improper time) ( 1 - v[sup:3q16qwo5]2[/sup:3q16qwo5]/c[sup:3q16qwo5]2[/sup:3q16qwo5])[sup:3q16qwo5]-1/2[/sup:3q16qwo5]

Otherwise you get the ridiculous claim: "the guy on the rocketship sees the earth moving so he thinks the people on earth are experiencing time dilation". Noboby "feels" like their experiencing time dilation. It's only when they will compare notes that they will realize that their clock was ticking differently, or that one looks younger than the other. The effect is real, even though the people on the rocketship don't feel it, they will experience time dilation, not the people on earth.

Given the fact that you're being pretty shitty about your posting (and I'm not sure WHY you're acting this way.... you were welcomed here with open arms)   ANYway........  I am learning more about why I am skinny on my broom.



I don't like learning with a bad taste in my mouth tho.
just sayin........
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on June 11, 2013, 11:26:11 AM
Quote from: "WitchSabrina"
Quote from: "josephpalazzo"I'm making it ugly when someone with superficial understanding is posting as if he were a specialist in that field, which he clearly is not.

As I said in another post to plu, there are too many ignoramuses posting on the internet. So we have a Republican party dedicated to put creationism in the science class, and a Republican senator sitting on the science committee, who knows nothing about science, doesn't even believe in evolution or global warming, yet has the power to decide who is going to get a grant in science. Enough of this ignorance, and pardon me if I want to bring some light in this sad, pathetic world.

And the irony is atheists ranting about theists, accusing them of being willfully ignorant. Perhaps those atheists should look in the mirror before making that accusation.


Not for nothing but we've had **experts** on this or that come stomping through here before.  And likely we will again.

Now --- there's two ways to go about slinging your expertise around:  There's the asshole method of calling long time members morons (aka thinking Very highly of ones self)  And there's the more respectful, professional method of just sharing your opinions or know-how in the form of adding data to the thread.  That shared data can lead to even more conversations.  Being a forum and all - wow - imagine that? Conversations.   :shock:  :shock:
Sometimes we find out much about a person's character - not by What they know - but rather how they choose to share what they know.

or


you can just become a newly-resident asshole and be known as such.

The choice - of course - is always yours.


Ask anyone here - but I can get fiercely loyal for my friends and how they are treated.   They don't even have to be right 100% of the time.    This IS A FORUM -- aka human interaction-- many of different styles and different methods will post here.  You can BE part of the forum or just be stubborn and nasty towards forum members.
I officially ASK that you consider what I am saying to you - here - Now.
My suggestion?  Back down a notch on shoving your expertise down everyone's throat.  No matter How correct you are - that method never ever works.  Like ever.

cheers

Why didn't you apply the same "morality" to your friends when one of them accused me of trying to fool people in this forum when really I was just trying to help the guy?!?

viewtopic.php?f=81&t=1103&start=30 (http://atheistforums.com/viewtopic.php?f=81&t=1103&start=30)

As far as I'm concerned, you can put me "on ignore", if that feature still exists, it won't be a great loss.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on August 25, 2013, 02:05:39 AM
Quote from: "josephpalazzo"You're free to listen to idiots and quacks. I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who  believe in unacceptable religious beliefs, like vaginal mutilation. Do you think we should respect that?! Why?

lol, I just saw this -- so posting erroneous information is of the same moral failing as chopping off labia majoræ, and deserves the same calumny?

Say, are you a math major?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 26, 2013, 10:23:35 AM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"You're free to listen to idiots and quacks. I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who  believe in unacceptable religious beliefs, like vaginal mutilation. Do you think we should respect that?! Why?

lol, I just saw this -- so posting erroneous information is of the same moral failing as chopping off labia majoræ, and deserves the same calumny?

Say, are you a math major?


Let me know if a math major can write a blog like this one:

strings of ideas (//http://soi.blogspot.ca/)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 26, 2013, 11:23:54 AM
QuoteThat's wrong. Get your facts straightened before spewing your ignorance.


That is also good advice for you JosephPalazzo. Read and learn Einstein:

--------------------------------------------------------------------------------
Common sense says:
 Any inertially-moving rod has only two endpoints;
 by not moving relative to each other, these two points
 produce a single constant intrinsic rod length (even
 if we are not currently able to determine said length).

 Therefore, if observers in various frames find different
 lengths for said rod, then this must be due to some
 observer-dependent process, and _not_ to the rod itself.

 Tom Roberts **agrees** by saying:

When you look at a building from directly in front,
 it appears to be wider than when you look at it from
 a corner. This effect does not affect the building
 itself, of course, and is purely due to your point
 of view. ... Similarly in SR, "length contraction"
 is purely a geometrical effect, an artifact of one's
 point of view ....

http://tinyurl.com/hvpej (http://tinyurl.com/hvpej)
 [Roberts to Nicolaaas Vroom 3-30-06]

 But what is the root physical cause of SR's
 observer-dependent "length contraction"?

 Tom Roberts tried to pin it down as follows:

Because the rod is moving, naturally the observer
 in A must mark both ends _simultaneously_ in
 frame A (which requires assistants) and then use
 a meterstick at rest in frame A to measure the
 length between the marks. Ultimately it is the
 DIFFERENCE IN SIMULTANEITY between frames A and
 B that is the source of the length contraction ....

http://tinyurl.com/hvpej (http://tinyurl.com/hvpej)
 [Roberts to GSS 3-19-06]

 While Roberts _believed_ he had located the root
 (or ultimate) cause as being "the difference in
 simultaneity," what we really need to know is
 What causes this difference in simultaneity?

 In other words, we need to find the physical cause
 of Einstein's relativity of simultaneity.

 Here is the story:

 Being unable to absolutely synchronize clocks, Einstein
 could not use clocks at events to correctly determine
 their occurrence times, so he had to fall back on using
 light signals sent from the events, merely _specifying_
 that the arrival times of these signals in each frame
 are to be used as the "occurrence times" of the events.

 Clearly, since each frame moves _differently_ relative
 to these signals, each frame's observers will see the
 signals arrive differently, so we can now see that the
 ultimate physical cause of the relativity of simultaneity
 is simply different frame movements wrt to light signals.

 Of course, if Einsteinian observers want to use _clocks_
 at the events instead of using light signals from the
 events, then all they have to do is make their clocks
 correspond to Einstein's light-signal scheme, and this
 can be done very simply by using midway-emitted light
 signals to start clocks on zero.

 Obviously, each frame's clocks will actually be started
 differently due to the different frame motions relative
 to the signals.

 For example, just as in Einstein's own train/embankment
 thought experiment, one frame's left clock may move
 toward its approaching signal, whereas the other clock
 will move away from its signal, so the clocks would not
 be started truly simultaneously.

 Then, if this frame's Einsteinian clocks are used to
 determine the time between two absolutely simultaneous
 events, then the clocks will report that the events
 did not occur simultaneously.

 And since events are observer-independent, this report
 flatly contradicts reality, as do all other such reports
 from all other Einsteinian frames' clocks (except those
 from the one frame whose clocks became truly synched by
 Einstein's light signals due to a lack of frame motion
 either toward or away from the signals).

 Given the simple fact that all but one of Einstein's
 frames contains absolutely asynchronous clocks due to
 absolutely different frame movements wrt the light
 signals used to set Einstein's clocks, we can at last
 _fully_ understand the relativistic "length contraction."

 Just as Tom Roberts said, this "contraction" is merely
 an artifact of Einstein's relativity of simultaneity,
 which, in turn, is an artifact of Einstein's absolutely
 asynchronous clocks. Einsteinian observers cannot truly
 simultaneously pin down the end points of a passing rod,
 so they mis-measure the rod, calling it shortened, and
 each frame's observers find a different length for one
 and the same passing rod, which, of course, cannot have
 but one physical length, as we noted above.

 BUT WHY STOP AT THE "LENGTH CONTRACTION"?

 It should be crystal clear to anyone by now that thanks
 to Einstein's asynchronous clocks, NONE of his two-clock
 results can possibly be correct.

 This means that special relativity's "time dilation,"
 "momentum variance" (sometimes called "mass increase"),
 "addition of velocities" (or velocity composition),
 transformation equations, and light's one-way, 2-clock
 speed are ALL INCORRECT.

 In other words, given absolutely synchronous clocks,
 exactly none of these relativistic results would occur,
 including the invariance of light's one-way speed.

 All of special relativity's results are due to Einstein's
 use of asynchronous clocks, which, in turn, are due to
 the use of a mere definition.

 Clearly, a _definition_ has nothing to do with the workings
 of the physical world, and cannot produce a scientific theory.

 --kk--
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 26, 2013, 01:05:18 PM
Fact 1: Relativity clearly predicts the mercury's orbital precession.
http://physics.ucr.edu/~wudka/Physics7/ ... ode98.html (http://physics.ucr.edu/~wudka/Physics7/Notes_www/node98.html)

Fact 2: Relativity clearly predicts the bending of light near the surface of the sun.
http://www.newtonphysics.on.ca/eclipse/ (http://www.newtonphysics.on.ca/eclipse/)

Fact 3: Relativity clearly predicts the half-life of muons from cosmic rays.
http://www.foothill.edu/~marasco/4dlabs/4dlab1.html (http://www.foothill.edu/~marasco/4dlabs/4dlab1.html)

Fact 4: GPS satellites must use Relativity to calculate the position of any user of GPS.
http://www.physics.org/article-questions.asp?id=55 (http://www.physics.org/article-questions.asp?id=55)

Fact 5: All high energy accelerating colliders, like the LHC, must use Relativity to give correct results.
http://www.sciencedaily.com/releases/20 ... 073117.htm (http://www.sciencedaily.com/releases/2001/12/011218073117.htm)

Fact 6: Relativity must be taken into account in order to explain atomic orbital of heavier elements of the periodic table.
http://en.wikipedia.org/wiki/Relativist ... _chemistry (http://en.wikipedia.org/wiki/Relativistic_quantum_chemistry)

These are just off the top of my head, but there are sufficient that those who think they can deny the theory should get their heads examined.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 26, 2013, 01:35:38 PM
Quotethose who think they can deny the theory should get their heads examined

So who is trying to do that?  :-s  It's quite obvious that your wrong saying solid objects actually contract when it is only apparent. Your interpretations are wrong not the theory. Off the top of your head---all those internet addresses. Wow! You must have a photographic memory besides your superior intelligent.  :roll: Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 26, 2013, 05:33:50 PM
Quote from: "Solitary"
Quotethose who think they can deny the theory should get their heads examined

So who is trying to do that?  :-s  It's quite obvious that your wrong saying solid objects actually contract when it is only apparent. Your interpretations are wrong not the theory. Off the top of your head---all those internet addresses. Wow! You must have a photographic memory besides your superior intelligent.  :roll: Solitary

If length contraction and time dilation are a figment of the imagination, then the whole theory collapses. You can't cherrypick only what you like and discard what you don't. The theory comes as a whole package.

The next thing people like you will say is that E = mc[sup:22sn4bxz]2[/sup:22sn4bxz] is a figment of the imagination... hmm, just a reminder:

(//http://i243.photobucket.com/albums/ff277/josephpalazzo/atomic_explosion.jpg) (//http://s243.photobucket.com/user/josephpalazzo/media/atomic_explosion.jpg.html)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: JonathanG on August 26, 2013, 11:15:41 PM
Quote from: "josephpalazzo"Let me know if a math major can write a blog like this one:

strings of ideas (//http://soi.blogspot.ca/)

Probably, if he had an special math symbol app.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 26, 2013, 11:55:27 PM
Quote from: "josephpalazzo"
Quote from: "Solitary"
Quotethose who think they can deny the theory should get their heads examined

So who is trying to do that?  :-s  It's quite obvious that your wrong saying solid objects actually contract when it is only apparent. Your interpretations are wrong not the theory. Off the top of your head---all those internet addresses. Wow! You must have a photographic memory besides your superior intelligent.  :roll: Solitary

If length contraction and time dilation are a figment of the imagination, then the whole theory collapses. You can't cherrypick only what you like and discard what you don't. The theory comes as a whole package.

The next thing people like you will say is that E = mc[sup:3cltr1a4]2[/sup:3cltr1a4] is a figment of the imagination... hmm, just a reminder:

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/atomic_explosion.jpg.html) ]

I never said it is a figment of the imagination. Don't put words in my mouth that aren't there! You don't understand that length contraction is apparent from a measurement that is relevant to an observer, not that it actually does in reality. As for time, isn't it obvious from the theory that time is "RELEVENT" to each observer also? In the theory there is no past, present, or future, accept relevant to an observer and their speed.  You may know math, but you sure don't understand the theories of relativity very well. I'm talking about in the real world and measurement, not in the world of mathematics. Solitary

[youtube:3cltr1a4]http://www.youtube.com/watch?v=G-R8LGy-OVs[/youtube:3cltr1a4]
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on August 27, 2013, 12:19:15 AM
Quote from: "josephpalazzo"
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"You're free to listen to idiots and quacks. I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who  believe in unacceptable religious beliefs, like vaginal mutilation. Do you think we should respect that?! Why?

lol, I just saw this -- so posting erroneous information is of the same moral failing as chopping off labia majoræ, and deserves the same calumny?

Say, are you a math major?


Let me know if a math major can write a blog like this one:

strings of ideas (//http://soi.blogspot.ca/)

I don't know.  But I'm pretty sure that link has nothing to do with my point, which is that drawing a moral equivalence between genital mutilation and posting incorrect behavior is pretty stupid.  

I will venture the guess that you're not well-educated in the liberal arts, though.  Feel free to demonstrate otherwise, by appealing to relevant arguments, and not irrelevant blogposts.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 27, 2013, 08:45:09 AM
Quote from: "Solitary"
Quote from: "josephpalazzo"If length contraction and time dilation are a figment of the imagination, then the whole theory collapses. You can't cherrypick only what you like and discard what you don't. The theory comes as a whole package.

The next thing people like you will say is that E = mc[sup:3tb3rfdw]2[/sup:3tb3rfdw] is a figment of the imagination... hmm, just a reminder:

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/atomic_explosion.jpg.html) ]

I never said it is a figment of the imagination. Don't put words in my mouth that aren't there! You don't understand that length contraction is apparent from a measurement that is relevant to an observer, not that it actually does in reality. As for time, isn't it obvious from the theory that time is "RELEVENT" to each observer also? In the theory there is no past, present, or future, accept relevant to an observer and their speed.  You may know math, but you sure don't understand the theories of relativity very well. I'm talking about in the real world and measurement, not in the world of mathematics. Solitary


Measuring the time dilation of the muon's half-life is real, NOT APPARENT. Like I said, you can't cherry-pick. If time dilation is real, so is length contraction, as time and space are on equal footing, a principle that has been successfully incorporated in QFT. You can spin all the philosophy you want, but the physics is real.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 27, 2013, 08:55:11 AM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"
Quote from: "Thumpalumpacus"lol, I just saw this -- so posting erroneous information is of the same moral failing as chopping off labia majoræ, and deserves the same calumny?

Say, are you a math major?


Let me know if a math major can write a blog like this one:

strings of ideas (//http://soi.blogspot.ca/)

I don't know.  But I'm pretty sure that link has nothing to do with my point, which is that drawing a moral equivalence between genital mutilation and posting incorrect behavior is pretty stupid.  

I will venture the guess that you're not well-educated in the liberal arts, though.  Feel free to demonstrate otherwise, by appealing to relevant arguments, and not irrelevant blogposts.


Since obviously you're an ignoramus in matters of math and physics, and incapable of discerning someone like solitary, who knows physics on a superficial level from someone who knows the subject deeply at a level you can't even phantom, I thought giving you a hint would help with a not-so ''irrelevant blogposts''. Apparently, it didn't help.

As to your point on moral equivalence, the genital mutilation stems from ignorance, something you seem to be very familiar with. You're looking at moral equivalence, I'm looking at the source of what causes so much suffering and injustice.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Plu on August 27, 2013, 09:01:09 AM
QuoteSince obviously you're an ignoramus in matters of math and physics, and incapable of discerning someone like solitary, who knows physics on a superficial level from someone who knows the subject deeply at a level you can't even phantom, I thought giving you a hint would help with a not-so ''irrelevant blogposts''. Apparently, it didn't help.

It's very obvious why it didn't help. To a layman's eye, there is no difference between in-depth blog posts of people who are good at physics, and in-depth blog posts who are just making shit up. Both are simply a long and extremely complicated piece of math and physics that may or may not be correct and for which we have no way to determine whether it's true or false.

So to answer the question of "could a math major write such a blog", the answer is: yes he could, and none of us would be the wiser.

It's kinda like asking someone "do you speak chinese" and them answering by posting something in an unknown asian language... unless we have a way to verify that it's actually chinese, we have no way to determine whether the answer given is meaningful or not.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on August 27, 2013, 09:15:34 AM
Quote from: "josephpalazzo"Since obviously you're an ignoramus in matters of math and physics, and incapable of discerning someone like solitary, who knows physics on a superficial level from someone who knows the subject deeply at a level you can't even phantom, I thought giving you a hint would help with a not-so ''irrelevant blogposts''. Apparently, it didn't help.

As to your point on moral equivalence, the genital mutilation stems from ignorance, something you seem to be very familiar with. You're looking at moral equivalence, I'm looking at the source of what causes so much suffering and injustice.

Treating them identically because they share the same wellspring is stupid.  One hurts your little feelings online, and the other inflicts lifelong physical harm.  

Thanks for playing, and stick to physics ... because you clearly have issues  assigning moral valuations.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 27, 2013, 10:56:58 AM
Quote from: "josephpalazzo"
Quote from: "Solitary"
Quote from: "josephpalazzo"If length contraction and time dilation are a figment of the imagination, then the whole theory collapses. You can't cherrypick only what you like and discard what you don't. The theory comes as a whole package.

The next thing people like you will say is that E = mc[sup:r77g0hz6]2[/sup:r77g0hz6] is a figment of the imagination... hmm, just a reminder:

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/atomic_explosion.jpg.html) ]

I never said it is a figment of the imagination. Don't put words in my mouth that aren't there! You don't understand that length contraction is apparent from a measurement that is relevant to an observer, not that it actually does in reality. As for time, isn't it obvious from the theory that time is "RELEVENT" to each observer also? In the theory there is no past, present, or future, accept relevant to an observer and their speed.  You may know math, but you sure don't understand the theories of relativity very well. I'm talking about in the real world and measurement, not in the world of mathematics. Solitary


Measuring the time dilation of the muon's half-life is real, NOT APPARENT. Like I said, you can't cherry-pick. If time dilation is real, so is length contraction, as time and space are on equal footing, a principle that has been successfully incorporated in QFT. You can spin all the philosophy you want, but the physics is real.

"Measuring the time dilation of the muon's half-life is real, NOT APPARENT"

Are you so dense you don't see you are saying your measurement relative to you is real and that the muons time relative to itself isn't . Do you think the muons time it would measure on its clock would be the same as yours? then you don't understand the concept of relativity. Also, according to a muon, if it could, would see your time on your clock different than you do.  :roll:  Did you even watch the video I provided? Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 27, 2013, 11:07:30 AM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"Since obviously you're an ignoramus in matters of math and physics, and incapable of discerning someone like solitary, who knows physics on a superficial level from someone who knows the subject deeply at a level you can't even phantom, I thought giving you a hint would help with a not-so ''irrelevant blogposts''. Apparently, it didn't help.

As to your point on moral equivalence, the genital mutilation stems from ignorance, something you seem to be very familiar with. You're looking at moral equivalence, I'm looking at the source of what causes so much suffering and injustice.

Treating them identically because they share the same wellspring is stupid.  One hurts your little feelings online, and the other inflicts lifelong physical harm.  

Thanks for playing, and stick to physics ... because you clearly have issues  assigning moral valuations.

He doesn't know physics very well either, he just knows the math. Logically a contradiction shows too things can't be true. This paradox in observation and measurement of time and length when approaching the speed of light is the very reason Einstein came up with the Special theory of relativity to solve the problem.
"solitary, who knows physics on a superficial level." That's funny because it is obvious that it applies to you. Just because you know the math doesn't mean you know the reality of relativity. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 27, 2013, 11:57:30 AM
QuoteThe Theory of Relativity for Dummies

Most people think it was Einstein who, in the first decade of the twentieth century, came up with the theory of relativity – as if Albert was quietly working away in his patent office in Switzerland and, entirely on his own, managed to come up with a completely new theory of space and time. Actually, it wasn't quite like that, but because the history of science is a dreadfully tedious subject, we will skip Albert's many predecessors and get straight to the best bits of the theory of relativity.

Question: Why is it called a theory of RELATIVITY? Why indeed.

Because time and length are no longer absolutes. You've got your digital watch on your wrist and a metre ruler on your desk. These seem like absolutes: a second and a centrimetre for you must be the same as they are for me, and the same as they are on Alpha Centauri. But they're not.

If I stay on my balcony while you start a career as an astronaut flying round the galaxy at an incredible speed (and it would have to be pretty close to the speed of light: 300,000km/sec), and if you could later whiz past my balcony so that we could somehow compare watches and rulers, your metre ruler would be smaller and your watch would be going slower than mine. (Actually that wouldn't be possible because the human eye can't spot things moving at that kind of speed, and spaceship rockets do nasty things to balconies that are only a few metres away. But if it were practically possible, it would be fun.)

While you're out in space travelling at some unbelievable speed nothing seems to you to have changed. It's only if you have a chance to compare measurements of time and length with those back home that you see that something odd has happened. Take time to think about this.

Q: All the introductions to Einstein talk about the twin paradox. What's that?

One 25 year old twin stays on earth while the other, fresh out of astronaut school, sets off on a space voyage travelling at 90% of the speed of light. After 10 years in space, with her mission accomplished, she turns round and heads back to earth. By the time she lands she knows from her on-board clock that 20 years have passed. She is now 45 years old. Fortunately, her study of relativity has prepared her for the shock when she sees her twin sister, who is now 71 years old. This is according to the general theory not the special theory.

Conclusion: Space travel, when it is really, really fast, is also time travel: you travel into the future without getting that much older yourself. Think about that!

So is everything relative?

Not exactly. Actually, the idea of time and length being relative to our speed was proposed first as a way of explaining an observation that puzzled everyone.

Some people in the nineteenth century devised a very sensitive piece of apparatus to measure the speed of light as we on earth rotate in space. The idea behind the experiment is easier to grasp if we think of spacecraft and the tiny particles of light called photons. If you were accelerating away from the sun wearing special goggles that enabled you to see individual photons, as you approached 300,000km/sec you would expect to see photons moving ever more slowly past the side window of the spacecraft. And common sense would say if you put your foot on the gas a bit more, you should overtake the photons and leave them crawling along behind as your spacecraft exceeds the speed of light.

What the scientists discovered, to everyone's surprise, was that if you move faster, light doesn't whiz past your window more slowly. It always whizzes past at the same speed. (In other words, the photons always win – nothing travels faster than light.)

To explain this bizarre finding, scientists (even before Einstein) suggested the following: the result only makes sense if, the faster you travel relative to the speed of light, the shorter your unit of length becomes and the slower your measurement of time becomes. This is to an observer in a different set of coordinates.

To an outside observer looking at your superfast starship, the photons might be moving past your side windows really slowly as your speed approaches 300,000km/sec, but if your on-board clock has slowed down by the same amount and your measurement of length has been compressed those same photons seen from inside the starship will seem to be whizzing past at the same speed as they had when you were still in first gear. Compared to an observer in another set of coordinates.

Is there any proof for all this?

Yes. Although spacecraft are still way too slow for astronauts to notice the effects of relativity, research into the behaviour of subatomic particles gives clear support to the theory. There is a laboratory deep within a Swiss mountain where they watch what happens to subatomic particles as they whiz through a circular tunnel attaining speeds close to that of light. Weird things happen, such as unstable particles staying alive for a lot longer than they normally would, and these weird things can only be expained by the theory of relativity. This is relative to an observer in a different set of coordinates.

Introduction to relativity: part 2

Q: I want to live as long as possible. Can relativity help me?

Time ticks by more slowly if you travel really fast, but this won't help you to enjoy living longer. On the spaceship nothing seems to have changed. If you make it to 80, despite all the health risks of space travel (osteoporosis, exposure to some really nasty radiation, etc) you will still look old and wrinkled. You would, however, be able to come back to earth and find that you had lived longer than your old mates (now at peace in the cemetery) but that doesn't sound like fun, so those who want to live longer would be better off sticking to a healthy diet and regular exercise, coupled with marriage and a sincere belief in God (on average, married believers live longer than unmaried atheists).  :Hangman:  Right, and they think they will never die.

Is there just one theory of relativity?

Unfortunately, there are two. The earlier one about space and time and the speed of light is known as the special theory of relativity. Later, Einstein realised he had made a few important omissions: gravity and acceleration (which turned out to have some striking similarities). So he developed the general theory of relativity to add to and complete the earlier theory. Again, Einstein wasn't the first to say some pretty weird things about light and gravity and space, but we're not going to bother with the boring historical details.

 Let's concentrate on the weird stuff.

What's weird about reality according to the general theory of relativity?
Well, for one, space is curved.

Eh?
If space wasn't curved, whenever we shone a beam of light (like a laser) it would travel in a line that would seem perfectly straight from wherever you were in the universe, and it would go on for ever and ever in the same direction. This is exactly as Euclid would have predicted (Euclid being the ancient Greek guy who was the founding father of high school geometry, and who assumed that space just had to be flat). This is not what happens, though. Light is bent by gravity, so a beam of light passing through galaxies curves when it comes close to a strong gravitational field.
 
Some people even think that gravity bends the space of the entire universe into a huge sphere. In practise, this would mean that if you tried to shine a laser beam out beyond the edge of the universe, gravity would bend it and send it in a huge circle running round the perimeter of the universe. (There would be no way of looking beyond or travelling beyond the edge of a universe like this.)
 
Is that about as weird as it gets?

Not exactly. The theory predicted (not for the first time) the existence of black holes. If gravity bends light then it is possible that if a star became dense enough, its gravitational field could be so great that the light it previously emitted could no longer escape.

Eh?
Let's begin like this: To launch a spaceship from the surface of the earth, it has to reach a velocity of about 40,000km/hour (11km/sec) otherwise gravity will either pull it into an orbit or back to the surface of the earth. This escape velocity increases relative to the size of the planet or the star (or even the galaxy) and its density. From the surface of the sun (much bigger and slightly more dense) the escape velocity would be 624km/sec. That would cause problems for terrestrial spacecraft but it causes no problems for light (travelling at 300,000km/sec).

When stars reach the end of their life strange things start to happen and they start to collapse. Eventually the atoms are squeezed together so tightly that their nucleii start to touch one another. That makes collapsed stars incredibly dense, the consequence of which is an incredibly strong gravitational field. If this were to happen to our sun, and if it were to become so compact that its diameter were a mere 1.47 km, gravity at the surface would be so high that the light of the dying star would no longer be able to escape.
As one physicist put it in the 1920's:

"There could come a time when the sun is shrouded in darkness, not because it has no light to emit but because its gravitational field will be impermeable to light."

The sun would have become a black hole.
Hang on. If a collapsed star can become a black hole, black holes can't really be holes, can they?
True. Actually, they weren't originally called black holes, and the word "hole" is a bit confusing because it makes you think that there is really nothing there, which isn't true because there is only a black hole when there is something which is either very very big or very very dense.

Another thing. Didn't you say light always travels at 300,000km/sec? Now you tell us that gravity makes light travel more slowly and could even bring it to a standstill.
 
If you were somewhere near a black hole and you measured the speed of light coming from your on-board laser, you would be disappointed to find it was still travelling at the usual speed. This is because gravity also does weird things to the clocks and rulers you would use to measure the speed of light. Close to very strong sources of gravity clocks tick away more slowly and rulers shrink (not that you would notice this inside the spaceship). These distortions of time and space are what they call a warp in spacetime. All to an observer outside a black hole.

If black holes do weird things to clocks, could they help me live longer?
If you could find a nearby black hole that was spinning, you could fly your spaceship into the whirling ring of material around it, and then with a quick burst from your booster rockets you could pull the ship out of the orbit before it got sucked into the blackness. Your on-board atomic clock might indicate that the hair-raising trip just lasted a couple of hours. But back on the mother ship hundreds of years might have elapsed. Again, all your old mates would be dead, which isn't much fun.
 
However, there is a happier lesson to be learnt for those of us back on earth. You should bear in mind that clocks tick slower in stronger gravitational fields when you next look for somewhere new to live. Physicists have put atomic clocks (that can measure a billionth of a second) in the basements and on the top floors of skyscrapers, and they have proved that clocks in basements run more slowly. So you should stop looking for a room with a view, you should get all your mates together and share one big flat underground.
As compared to another clock in a different set of coordinates.  This is why time is not absolute but relative to an observer and their speed.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on August 27, 2013, 12:21:19 PM
Sorry to have a blonde moment - but HOW can math be a debate?  Isn't math.......  math?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 27, 2013, 12:37:36 PM
Quote from: "WitchSabrina"Sorry to have a blonde moment - but HOW can math be a debate?  Isn't math.......  math?


Math is not debated, but whether a measurement of time and space is relative or not. I say it is, and JosephPalazzo thinks its not that it's real time dilation and not just a reading on a clock by an observer and actual shrinkage of a solid object instead of a measurement by an observer.

This means you are not really thinner, but it just appears to be so when you zip past on your broom to an observer standing still compared to you, and if the observer was going with you on his broom  =P~  he would see you as you really are which is lovely. :shock:   :lol:   Sorry! Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 27, 2013, 03:44:17 PM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"Since obviously you're an ignoramus in matters of math and physics, and incapable of discerning someone like solitary, who knows physics on a superficial level from someone who knows the subject deeply at a level you can't even phantom, I thought giving you a hint would help with a not-so ''irrelevant blogposts''. Apparently, it didn't help.

As to your point on moral equivalence, the genital mutilation stems from ignorance, something you seem to be very familiar with. You're looking at moral equivalence, I'm looking at the source of what causes so much suffering and injustice.

Treating them identically because they share the same wellspring is stupid.  One hurts your little feelings online, and the other inflicts lifelong physical harm.

And who says I'm treating them equally??? Before writing stupidities, use your head, if you have one!!!



QuoteThanks for playing, and stick to physics ... because you clearly have issues  assigning moral valuations.

Don't thank me, you're the idiot who blurped some idiocy regarding my post. Next time, mind your own business if you can't make some intelligent comment. You're a waste.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 27, 2013, 03:59:04 PM
Solitary, your post is full of so many errors, that I won' bother with it. The only advice I have for you is to study the theory from textbooks that have stood the test of time, and not from the internet.

Here's a partial list ( I have these books myself):

A First Course in General Relativity [Hardcover]
Bernard Schutz (//http://www.amazon.com/A-First-Course-General-Relativity/dp/0521887054/ref=sr_1_6?ie=UTF8&qid=1377633136&sr=8-6&keywords=bernard+schultz)

General Relativity [Paperback]
Robert M. Wald (//http://www.amazon.com/General-Relativity-Robert-M-Wald/dp/0226870332/ref=sr_1_1?ie=UTF8&qid=1377633234&sr=8-1&keywords=Wald%2C+relativity)

Gravity: An Introduction to Einstein's General Relativity [Hardcover]
James B. Hartle (//http://www.amazon.com/Gravity-Introduction-Einsteins-General-Relativity/dp/0805386629/ref=sr_1_1?s=books&ie=UTF8&qid=1377633315&sr=1-1&keywords=hartle+relativity)

Gravitation (Physics Series) [Paperback]
Charles W. Misner, Kip S. Thorne , John Archibald Wheeler (//http://www.amazon.com/Gravitation-Physics-Charles-W-Misner/dp/0716703440/ref=sr_1_1?s=books&ie=UTF8&qid=1377633387&sr=1-1&keywords=Gravitation%2C+wheeler)

If you don't want to spend that much money, you can use Sean Carroll online lecture notes at:

http://arxiv.org/pdf/gr-qc/9712019.pdf (http://arxiv.org/pdf/gr-qc/9712019.pdf)

However, it won't give the overall perspective when you study a subject from different authors. But Carroll's notes are better than nothing.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 02:38:20 AM
Quotehttp://arxiv.org/pdf/gr-qc/9712019.pdf

This lecture is of the relationship of the special theory of relativity with regards to spacetime, not the theory itself.  :roll: Why do you insist in complicating the issue at hand with mathematics instead of plain English?

The idea that time being relative lies at the very heart of Einstein's special theory of relativity. You may think that time is fixed, that it can't slow down or speed up---especially external time. But Einstein would disagree.

Time passes differently for a person at rest than it does for someone at a great speed in "RELATION" to the person standing still. But for both people, "their" experience of time is real time. Neither of them is aware that time is passing by differently for them.

Now lengths don't change for a person approaching the speed of light. For them, objects appear to be the same length as always. The change is "PERCIEVED" by an observer who is watching an object approach the speed of light. remember that the special theory deals with two frames of reference: the person approaching the speed of light and an observer at rest.

Almost all of the "paradoxes" associated with SR result from a stubborn persistence of
the Newtonian notions of a unique time coordinate and the existence of "space at a single
moment in time." By thinking in terms of spacetime rather than space and time together,
these paradoxes tend to disappear.

The concept of absolute time was overthrown by the special theory of relativity, in which time was no longer an independent quantity on its own but was just one direction in a four-dimensional continuum called spacetime. In special relativity, different observers traveling at different velocities move through spacetime on different paths.

Each observer has his or her own measurement of time along the path he or she is following, and different observers will measure different intervals of time between events. Thus in special relativity there is no unique absolute time that can be labeled for events. However, the spacetime of special relativity is flat. This means that in special relativity, the time measured by any freely moving observer increases smoothly in spacetime from minus infinity in the infinite past to plus infinity in the infinite future.

So the bottom line is that Sabrina on her broom will be "perceived" to be thinner by an observer standing still when in fact she won't be.  :P  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Plu on August 28, 2013, 03:08:14 AM
Quote from: "WitchSabrina"Sorry to have a blonde moment - but HOW can math be a debate?  Isn't math.......  math?

There's actually a number of debates going around in the world of math about a number of topics that simply aren't very clear-cut. Math is not unchanging, nor unique, and has its own debates. Particularly in the field of infinity as I remember, there are a lot of divergent opinions on how it should work.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on August 28, 2013, 06:28:45 AM
Quote from: "Plu"
Quote from: "WitchSabrina"Sorry to have a blonde moment - but HOW can math be a debate?  Isn't math.......  math?

There's actually a number of debates going around in the world of math about a number of topics that simply aren't very clear-cut. Math is not unchanging, nor unique, and has its own debates. Particularly in the field of infinity as I remember, there are a lot of divergent opinions on how it should work.

Actually, I'm not that simple minded Plu.  LOL  I was trying to make a joke and ease the conversation.  But I agree math is not unchanging.  
cheers
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Plu on August 28, 2013, 06:31:03 AM
Ah, ok :P It's hard to tell sometimes. Plenty of people really think like that.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on August 28, 2013, 07:26:49 AM
Quote from: "Solitary"Why do you insist in complicating the issue at hand with mathematics instead of plain English?

The maths actually makes it easier to understand.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 10:07:50 AM
That like saying explaining something in Greek makes it easier to understand.

There is a very simple way to resolve this debate. All Joseph has to do is show us in his own words, like I have, what the special theory of relativity is about, or even post from one of his books he listed what it says, and not a bunch of mathematics that most people don't understand.  :roll:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 28, 2013, 10:57:35 AM
Quote from: "Solitary"
Quotehttp://arxiv.org/pdf/gr-qc/9712019.pdf

This lecture is of the relationship of the special theory of relativity with regards to spacetime, not the theory itself.  :roll:

This is where you show your upmost ignorance. I'm not going to bother with you.

Read the first page:

QuoteThese notes represent approximately one semester's worth of lectures on introductory
general relativity for beginning graduate students in physics.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 11:09:32 AM
You can't even give us what the books you recommended say about the special theory of relativity. And you cannot even show what it means in your own words.  :roll:

You committed a fallacy of omission with your quote. Here is the complete quote:

This is what your site says: These notes represent approximately one semester's worth of lectures on introductory general relativity for beginning graduate students in physics. Topics include manifolds, Riemannian geometry, Einstein's equations, and three applications: gravitational radiation, black holes, and cosmology. Please explain how that is showing the theory and not talking about how it relates to spacetime!

You don't understand the theory, admit it!  :roll:


Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 11:42:04 AM
If there is anyone that is actually interested in learning what the special theory of relativity is about instead of reading insults about my knowledge of the subject or how stupid I am, here is what the theory is about:

Suppose that you are moving toward something that is moving toward you. If you measure its speed, it will seem to be moving faster than if you were not moving. Now suppose you are moving away from something that is moving toward you. If you measure its speed again, it will seem to be moving more slowly. This is the idea of "relative speed."


QuoteBefore Albert Einstein, scientists were trying to measure the "relative speed" of light. They were doing this by measuring the speed of starlight reaching the Earth. They expected that if the Earth were moving toward a star, the light from that star should seem faster than if the Earth were moving away from that star. They noticed that no matter who performed the experiments, where they were performed, or what starlight they used, the measured speed of light in a vacuum was always the same.

Einstein said this happens because there is something unexpected about length and duration. He thought that as the Earth moves through space, all measurable durations change (ever so slightly). Any clock used to measure some duration will give a duration off by exactly the right amount so that the speed of light remains the same. Mentally constructing a "light clock" allow us to better understand this remarkable fact for the case of a single light wave. Notice it says measurable.

Also, Einstein said that as the Earth moves through space, all measurable lengths change (ever so slightly). Any device measuring length will give a length off by exactly the right amount so that the speed of light remains the same.

Other scientists before Einstein had written about light seeming to go the same speed no matter how it was observed. What made Einstein's theory so revolutionary is that it considers the measurement of the speed of light to be constant by definition, in other words it is a law of nature. This has the remarkable implications that speed-related measurements, length and duration, change in order to accommodate this.

The Lorentz transformations
The mathematical bases of special relativity are the Lorentz Transformations, which mathematically describe the views of space and time for two observers who are moving with respect to each other but are not experiencing acceleration.

To define the transformations we use a Cartesian coordinate system to mathematically describe the time and space of "events".

Each observer can describe an event as the position of something in space at a certain time, using coordinates (x,y,z,t).

The location of the event is defined in the first three coordinates (x,y,z) in relation to an arbitrary center (0,0,0) so that (3,3,3) is a diagonal going 3 units of distance (like meters or miles) out in each direction.
The time of the event is described with the fourth coordinate t in relation to an arbitrary (0) point in time in some unit of time (like seconds or hours or years).

Let there be an observer K who describes when events occur with a time coordinate t, and who describes where events occur with spatial coordinates x, y, and z. This is mathematically defining the first observer whose "point of view" will be our first reference.

Let us specify that the time of an event is given: by the time that it is observed t(observed) (say today, at 12 o'clock) minus the time that it took for the observation to reach us.

This can be calculated as the distance from the observer to the event d(observed) (say the event is on a star which is 1 light year away, so it takes the light 1 year to reach the observer) divided by c, the speed of light (several million miles per hour), which we define as being the same for all observers.

This is correct because distance, divided by speed gives the time it takes to go that distance at that speed (e.g. 30 miles divided by 10 mph: give us 3 hours, because if you go at 10 mph for 3 hours, you reach 30 miles). So we have:
 
This is mathematically defining what any "time" means for any observer.
Now with these definitions in place, let there be another observer K' who is
moving along the x axis of K' at a rate of v,
has a spatial coordinate system of x' , y' , and z' ,
where x' axis is coincident with the x axis, and with the y' and z' axes - "always being parallel" to the y and z axes.

This means that when K', the second observer, gives a location like (3,1,2), the x (which is 3 in this example) is the same place that K, the first observer would be talking about, but the 1 on the y axis or the 2 on the z axis are only parallel to some location on the K' observer's coordinate system. and
where K and K' are coincident at t = t' = 0

This means that the coordinate (0,0,0,0) is the same event for both observers.
In other words, both observers have (at least) one time and location that both agree on, which is location and time zero.

 
Mass, energy and momentum
In special relativity, the momentum p and the energy E of an object as a function of its rest mass m0 are a. A frequently made error (also in some books) is to rewrite these equation using a "relativistic mass" (in the direction of motion) of  . The fact why this is incorrect is that the light, for example, has no mass, but has energy. If we use this formula, the photon (particle of light) has a mass, which is according to experiments incorrect.

In special relativity, energy and momentum are related by the equation
 .
History
The need for special relativity arose from Maxwell's equations of electromagnetism, which were published in 1865. It was later found that they call for electromagnetic waves (such as light) to move at a constant speed (i.e., the speed of light).

To have James Clerk Maxwell's Equations be consistent with both astronomical observations, and Newtonian physics Maxwell proposed in 1877 that light travels through an ether which is everywhere in the universe.
In 1887, the famous Michelson-Morley experiment tried to detect the "ether wind" generated by the movement of the Earth. The persistent null results of this experiment puzzled physicists, and called the ether theory into question.

In 1895, Lorentz and Fitzgerald noted that the null result of the Michelson-Morley experiment could be explained by the ether wind contracting the experiment in the direction of motion of the ether. This effect is called the Lorentz contraction, and (without ether) is a consequence of special relativity.

In 1899, Lorentz first published the Lorentz Equations. Although this was not the first time they had been published, this was the first time that they were used as an explanation of the Michelson-Morley experiment's null result, since the Lorentz contraction is a result of them.

In 1900, Poincaré gave a famous speech in which he considered the possibility that some "new physics" was needed to explain the Michelson-Morley experiment.

In 1904, Lorentz showed that electrical and magnetic fields can be modified into each other through the Lorentz transformations.

In 1905, Einstein published his article introducing special relativity, "On the Electrodynamics of Moving Bodies", in Annalen der Physik. In this article, he presented the postulates of relativity, derived the Lorentz transformations from them, and (unaware of Lorentz's 1904 article) also showed how the Lorentz Transformations affect electric and magnetic fields.

Later in 1905, Einstein published another article presenting E = mc2.
In 1908, Max Planck endorsed Einstein's theory and named it "relativity". In that same year, Minkowski gave a famous speech on Space and Time in which he showed that relativity is self-consistent and further developed the theory. These events forced the physics community to take relativity seriously. Relativity came to be more and more accepted after that.

In 1912 Einstein and Lorentz were nominated for the Nobel prize in physics due to their pioneering work on relativity. Unfortunately, relativity was so controversial then, and remainded controversial for such a long time that a Nobel prize was never awarded for it.

Experimental confirmations
The Michelson-Morley experiment, which failed to detect any difference in the speed of light based on the direction of the light's movement.

Fizeau's experiment, in which the index of refraction for light in moving water cannot be made to be less than 1. The observed results are explained by the relativistic rule for adding velocities.

The energy and momentum of light obey the equation E = pc. (In Newtonian physics, this is expected to be  .)
The transverse doppler effect, which is where the light emitted by a quickly moving object is red-shifted due to time dilation.

The presence of muons created in the upper atmosphere at the surface of the Earth. The issue is that it takes much longer than the half-life of the muons to get down to the surface of the Earth even at nearly the speed of light. Their presence can be seen as either being due to time dilation (in our view) or length contraction of the distance to the surface of the Earth (in the muon's view). As measured!

Particle accelerators cannot be constructed without accounting for relativistic physics.

Notes
[1] Observations of binary stars show that light takes the same amount of time to reach the Earth over the same distance for both stars in such systems. If the speed of light was constant with respect to its source, the light from the approaching star would arrive sooner than the light from the receding star. This would cause binary stars to appear to move in ways that violate Keppler's Laws, but this is not seen.

[2] The second postulate of special relativity (that the speed of light is the same for all observers) contradicts Newtonian physics.

[3] Since the Earth is constantly being accelerated as it orbits the Sun, the initial null result was not a concern. However, that did mean that a strong ether wind should have been present 6 months later, but none was observed.

References
? Light in different media may travel at different speeds.
W. Rindler, Introduction to Special Relativity, 2nd edition, Oxford Science Publications, 1991, ISBN 0-19-853952-5.
Web article on the history of special relativity
Relativity Calculator - Learn Special Relativity Mathematics The mathematics of special relativity presented in as simple and comprehensive manner possible within philosophical and historical contexts.


I'm sure a physicist from Oxford knows what he's talking about. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on August 28, 2013, 01:53:08 PM
Quote from: "Solitary"This is what your site says: These notes represent approximately one semester's worth of lectures on introductory general relativity for beginning graduate students in physics. Topics include manifolds, Riemannian geometry, Einstein's equations, and three applications: gravitational radiation, black holes, and cosmology. Please explain how that is showing the theory and not talking about how it relates to spacetime!

That's the kind of prerequisite stuff you need to know to understand what's going on.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 28, 2013, 02:28:58 PM
Quote from: "Solitary"You can't even give us what the books you recommended say about the special theory of relativity. And you cannot even show what it means in your own words.  :roll:

You committed a fallacy of omission with your quote. Here is the complete quote:

This is what your site says: These notes represent approximately one semester's worth of lectures on introductory general relativity for beginning graduate students in physics. Topics include manifolds, Riemannian geometry, Einstein's equations, and three applications: gravitational radiation, black holes, and cosmology. Please explain how that is showing the theory and not talking about how it relates to spacetime!

You don't understand the theory, admit it!  :roll:


Solitary

Do you know what beginning graduate student entails? You would need a BSc with a minimum of a major in physics - a semester course in mechanics, wave mechanics, thermodynamics, a first course in QM and a first course in SR. Along with that, a course in calculus of one variable, a second course in calculus of multivariables, an intro into group theory, topology and differential geometry. This spread over 4 years,and then you would be ready to tackle Sean Carroll's lectures on General Relativity. It is a course in GR, in case you've haven't read the first page. BTW, this is a beginning course. More advanced courses  would deal with subjects like Cartan structure algebra, Null tetrads, Petrov Classification, Killing vectors and Conformal Metrics, to name a few topics. Now you haven't studied one tenth of this material, and you think you can spread your nonsense as if you are an expert. You're not, and if you continue along that line I will call you an intellectual fraud.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 02:42:35 PM
Your ad hominems or so-called claim to have studied the subject without being able to express it in the written language do not impress me or show I'm wrong.  I never said I was an expert, only that you don't understand the theory of special relativity. And how am I spreading nonsense when I post what it is by a physicist that is saying the same thing from Oxford? As for a beginning student, how about one that graduated with a degree in physics and all the higher mathematics in college 50 years ago. All you have to do is actually post from one of your books on the theory or what you know about the theory of special relativity in English, and then I and others will believe you know the subject.  :popcorn:  Soliitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 28, 2013, 03:18:28 PM
Quote from: "Solitary"Your ad hominems or so-called claim to have studied the subject without being able to express it in the written language do not impress me or show I'm wrong
.

This is a clear sign of your ignorance. The only way you can do physics, is by doing the math. It's not philosophy, which you can do by ruminating in your ivory tower. If you're not willing to do the hard work, which is going through every derivation,  work out the problems at the end of each chapter, write the exams to show you have acquired some mastery of the subject, get a degree (BSc) then move on to a higher dregree (PhD) then you're just an amateur, a wacko or an intellectual fraud, as there are plenty of those roaming on the internet, posting like you are in this forum.

QuoteI never said I was an expert, only that you don't understand the theory of special relativity.

Which part would that be that I don't understand? Secondly, you're incapable to make that judgment call.

QuoteAnd how am I spreading nonsense when I post what it is by a physicist that is saying the same thing from Oxford?

Cut and paste from a website doesn't make you an expert. Nor does it show that you understand any of that material. I gave you a list of textbooks to study from. What you're doing is picking up whatever from a website you think happens to confirm your limited knowledge.

QuoteAs for a beginning student, how about one that graduated with a degree in physics and all the higher mathematics in college 50 years ago.

Anyone who has studied this stuff 50 years ago, and did not update since, will be behind as GR evolved considerably in that span of times. The greatest quest in physics is to quantize gravity, and GR looms large over this endeavor. So anyone who didn't bother with keeping in touch with the research done over the last 50 years would be totally lost today.


QuoteAll you have to do is actually post from one of your books on the theory or what you know about the theory of special relativity in English, and then I and others will believe you know the subject.  :popcorn:  Soliitary

I don't have to look at any of my books. If you want to ask questions then do so, and I will answer. But don't give me a post full of assertions that are baseless and totally off the mark. I won't bother with that. And don't give me a  cut and paste, which accomplishes absolutely nothing as that gives no clue where your understanding is at. Ask me intelligent questions, and I will deliver as best as I can.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 03:33:34 PM
Still waiting!  :popcorn:   :lol:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 28, 2013, 03:41:44 PM
I'm beginning to believe that your reading skills are very limited. Sorry If I called you a wacko, you're really a retard.   :(
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on August 28, 2013, 04:08:50 PM
Quote from: "Solitary"You can't even give us what the books you recommended say about the special theory of relativity. And you cannot even show what it means in your own words.
Because you can't fully explain a mathematical concept without using math.  A verbal explanation of SR is like a portrait of a man done as a stick figure - most of the important stuff is missing.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 28, 2013, 10:26:34 PM
Then how do you explain the video and explanation by a physicist I posted, or the many books without math?
Do you have any idea how that sounds to say it can't be explained without math when it obviously can be. :roll:  Wow!

Read and learn:

Even if it can't be fully explained the funda"mental" basics can and that is all I'm asking for.

How can  Andrew Zimmerman Jones and Daniel Robbins explain it in words if JosephPalazzo can't?

By the way, this is from the book: Einsteins Special Theory For Dummies.
 
In 1905, Albert Einstein published the theory of special relativity, which explains how to interpret motion between different inertial frames of reference — that is, places that are moving at constant speeds relative to each other.

Einstein explained that when two objects are moving at a constant speed as the relative motion between the two objects, instead of appealing to the ether as an absolute frame of reference that defined what was going on. If you and some astronaut, Amber, are moving in different spaceships and want to compare your observations, all that matters is how fast you and Amber are moving with respect to each other.

Special relativity includes only the special case (hence the name) where the motion is uniform. The motion it explains is only if you're traveling in a straight line at a constant speed. As soon as you accelerate or curve — or do anything that changes the nature of the motion in any way — special relativity ceases to apply. That's where Einstein's general theory of relativity comes in, because it can explain the general case of any sort of motion.

Einstein's theory was based on two key principles:
The principle of relativity: The laws of physics don't change, even for objects moving in inertial (constant speed) frames of reference.

The principle of the speed of light: The speed of light is the same for all observers, regardless of their motion relative to the light source. (Physicists write this speed using the symbol c.)

The genius of Einstein's discoveries is that he looked at the experiments and assumed the findings were true. This was the exact opposite of what other physicists seemed to be doing. Instead of assuming the theory was correct and that the experiments failed, he assumed that the experiments were correct and the theory had failed.

In the latter part of the 19th century, physicists were searching for the mysterious thing called ether — the medium they believed existed for light waves to wave through. The belief in ether had caused a mess of things, in Einstein's view, by introducing a medium that caused certain laws of physics to work differently depending on how the observer moved relative to the ether. Einstein just removed the ether entirely and assumed that the laws of physics, including the speed of light, worked the same regardless of how you were moving — exactly as experiments and mathematics showed them to be!

Unifying space and time
Einstein's theory of special relativity created a fundamental link between space and time. The universe can be viewed as having three space dimensions — up/down, left/right, forward/backward — and one time dimension. This 4-dimensional space is referred to as the space-time continuum.

If you move fast enough through space, the observations that you make about space and time differ somewhat from the observations of other people, who are moving at different speeds.
You can picture this for yourself by understanding the thought experiment depicted in this figure. Imagine that you're on a spaceship and holding a laser so it shoots a beam of light directly up, striking a mirror you've placed on the ceiling. The light beam then comes back down and strikes a detector.

However, the spaceship is traveling at a constant speed of half the speed of light (0.5c, as physicists would write it). According to Einstein, this makes no difference to you — you can't even tell that you're moving. However, if astronaut Amber were spying on you, as in the bottom of the figure, it would be a different story.
Amber would see your beam of light travel upward along a diagonal path, strike the mirror, and then travel downward along a diagonal path before striking the detector.

In other words, you and Amber would see different paths for the light and, more importantly, those paths aren't even the same length. This means that the time the beam takes to go from the laser to the mirror to the detector must also be different for you and Amber so that you both agree on the speed of light.
This phenomenon is known as time dilation, where the time on a ship moving very quickly appears to pass slower than on Earth.

As strange as it seems, this example (and many others) demonstrates that in Einstein's theory of relativity, space and time are intimately linked together. If you apply Lorentz transformation equations, they work out so that the speed of light is perfectly consistent for both observers.

This strange behavior of space and time is only evident when you're traveling close to the speed of light, so no one had ever observed it before. Experiments carried out since Einstein's discovery have confirmed that it's true — time and space are perceived differently, in precisely the way Einstein described, for objects moving near the speed of light.

Unifying mass and energy
The most famous work of Einstein's life also dates from 1905 (a busy year for him), when he applied the ideas of his relativity paper to come up with the equation E=mc2 that represents the relationship between mass (m) and energy (E).

In a nutshell, Einstein found that as an object approached the speed of light, c, the mass of the object increased. The object goes faster, but it also gets heavier. If it were actually able to move at c, the object's mass and energy would both be infinite. A heavier object is harder to speed up, so it's impossible to ever actually get the particle up to a speed of c.

Until Einstein, the concepts of mass and energy were viewed as completely separate. He proved that the principles of conservation of mass and conservation of energy are part of the same larger, unified principle, conservation of mass-energy. Matter can be turned into energy and energy can be turned into matter because a fundamental connection exists between the two types of substance.

Now that wasn't so hard was it?

By the way, no matter how many people jump on the Band Wagon doesn't make me wrong anymore than it does when Christians do it. The basic theory of special relativity has not changed since I studied it anymore than the theory of Evolution has. Still waiting. I know why you won't by the way, because you can't because you just know the math and not what the theory is. Well maybe you do now since I posted it.  :popcorn: Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on August 29, 2013, 01:21:38 PM
Quote from: "Solitary"Then how do you explain the video and explanation by a physicist I posted, or the many books without math?
You can explain SR without math.  You can't fully explain it.  There's a difference.

QuoteIn a nutshell, Einstein found that as an object approached the speed of light, c, the mass of the object increased. The object goes faster, but it also gets heavier. If it were actually able to move at c, the object's mass and energy would both be infinite. A heavier object is harder to speed up, so it's impossible to ever actually get the particle up to a speed of c.
"For dummies" is right.  That's kinda-sorta correct, but the math demonstrating it is so trivial that anyone with the normal high school math education can understand it - and it's completely correct.

Explaining math without using math is like eating without food.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 29, 2013, 03:16:46 PM
QuoteYou can't fully explain it.

Again, I'm not asking him to fully explain it, just give the basics in his words. If he can't do that then he just knows the math and not what the theory is about. It's really not that hard, as you say, even dummies can do it. :roll:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 29, 2013, 05:55:31 PM
Quote from: "Colanth""For dummies" is right.  That's kinda-sorta correct, but the math demonstrating it is so trivial that anyone with the normal high school math education can understand it - and it's completely correct.

Explaining math without using math is like eating without food.


The funny part about Solitary is that he cuts and pastes things about SR that have be known for almost 100 years ago, and then he posts them as if this stuff is all new, and worst, he thinks he understands it. The guy is hopeless. Put him on ignore.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on August 29, 2013, 06:05:26 PM
Quote from: "Solitary"
QuoteYou can't fully explain it.

Again, I'm not asking him to fully explain it, just give the basics in his words. If he can't do that then he just knows the math and not what the theory is about.
What the theory is all about is the math.  Not everything in science can be adequately explained in lay terms.

QuoteIt's really not that hard, as you say, even dummies can do it.
Even dummies can understand an "explanation" that doesn't really explain the theory.  To actually understand the theory means understanding the math.  The stick figure isn't really the man, no matter how many dummies think it is.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 29, 2013, 11:35:03 PM
QuoteEven dummies can understand an "explanation" that doesn't really explain the theory.


 :-k  #-o  Lets see, an explanation of the special theory of relativity doesn't really explain it if it doesn't have math. Makes sense to me.  8-)  Thanks! Does this mean if someone can't explain the special theory of relativity in a way that a dummy can understand it they are smarter than a dummy? Hummm!  :-k  #-o  Why didn't I know that? I guess I really am stupid. OK. You or JosephPalazzo Show me with mathematics how Sabrina actually gets shorter as she reaches the speed of light and it's not just apparent to an observer watching her. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 29, 2013, 11:49:39 PM
Better yet, here is both, in words and math:


SPECIAL RELATIVITY

Central to the discussion of special relativity is the idea of an inertial frame (or reference). This is basically a coordinate system, which might be attached to an observed object or to the observer, which undergoes no acceleration. Consequently, the relative velocity between two inertial frames is necessarily constant, providing what we refer to as uniform motion.

Einstein based his 1905 theory on two postulates:

1. No physical measurement can distinguish one inertial frame from another.

2. The speed of light (in vacuum) is the same in all inertial frames, regardless of any motion of the source.

 
Postulate (1) is also known as the Principle of Relativity and is a generalization of the idea of Galileo: that uniform motion is undetectable by mechanical experiments. This Galilean Principle of Relativity accounts for the fact that there are no obvious effects of the earth's motion through space, as it orbits the sun (at a tangential speed of about 17 000 km/hr !). For example, objects released from the top of a tower fall vertically downwards (towards the centre of the earth), as they would if the earth were stationary and not at some angle which depends on the earth's tangential speed. Einstein thought that Galileo's principle should apply to the whole of physics, including electromagnetic phenomena.


Postulate (2) derives from the idea of Maxwell that light behaves as a travelling wave, containing oscillating electric and magnetic fields which can advance (propagate) in a vacuum at a speed, denoted by the symbol c , which depends only on two basic constants of electrostatic and magnetic theory. The fields require no medium for their existence, unlike the case of sound waves (for example) whose velocity within a gas (or liquid or solid) is affected by any motion of this medium.


Previously, physicists had assumed that light waves behave somewhat like sound, propagating though an invisible medium which they termed the (aluminiferous) ether. Attempts to measure the speed of the earth relative to the ether failed; in particular, the Michelson-Morley experiment (performed repeatedly between 1881 and 1930) showed that light travels with exactly the same speed in two perpendicular directions, which is impossible if the earth is moving (due to its orbit around the sun) through an ether.

Length contraction

From Einstein's two postulates, several properties follow as a matter of pure logic. One of these is an effect called length contraction: the measured length (in the direction of motion) of an object which is moving at uniform speed v relative to an observer is less than if the object were stationary. The length measured when there is no relative motion is called the proper length and all other lengths are called improper. The length-contraction effect can be expressed mathematically as:

 improper length = (1/gamma) (proper length)

where 1/gamma = (1 - v^2 / c^2)^(1/2) and is less than unity; here ^ means to the power of , so ^(1/2) means taking the square root. Since the value of c (= 3.00 x 10^8 m/s) is so large, length contraction is entirely negligible (e.g. 1 part in 2 x 10^12 for v = 1000 km/hr) for objects such a cars, trains and airplanes.

There is no change in dimensions of the object which are perpendicular to the relative velocity v ; therefore it might be expected that a fast-moving cube would appear squashed (in the direction of motion) in a high-speed photograph. However light from different parts of the cube takes different times to reach the camera, so the photograph is not a record of the object at a single instant of time. This illustrates the difference between a true measurement and a simple observation. In fact, the cube would appear as if it had been rotated (through a fixed angle), due to the combined effects of length contraction and the finite (limited) speed of light.

Magnetic force can be thought to arise from electrostatic interaction, plus the length-contraction effect. For example, a metal contains potentially-mobile negative electrons and an equal number of immobile positive charges. In the absence of any electrical current, two parallel wires exert no force on each other because the attractive forces (electrons in one wire attracting positive charge in the other, and vice versa) are exactly balanced by repulsions (electrons in one wire repelling those in the other, likewise for the positive charges).

 With an equal current travelling in the same direction in each wire, the repulsive forces are unchanged (there is no relative motion between the electrons or positive charges) but the attractions are increased, since the positive charge "sees" the distance between the moving electrons as contracted (equivalent to an increase in negative charge per unit length of the wire) or vice versa. This increase is seen as a net attractive force between the two wires, usually attributed to the magnetic effect of the currents. We can say that Special Relativity unites the concepts of magnetic and electrostatic force into a single electromagnetic force.

Time dilation


Another effect predicted by special relativity is time dilation : a clock moving at uniform speed relative to an observer would be measured to run slow, arising from the properties of space-time and not from the finite speed of light. By analogy with the above, we can define an interval of proper time as a difference in the readings of a clock which is stationary with respect to the observer; where there is relative motion, we measure an improper time interval.
 

improper time interval = (gamma) (proper time interval)

 
Since gamma > 1, the interval between ticks of a "moving" (relative to the observer) clock is greater than for a "stationary" clock, so "a moving clock runs slow". This effect has been verified by carrying highly-accurate atomic clocks aboard aircraft and comparing their "readings" with those of an identical clock which remained stationary. Although the difference in elapsed time is miniscule, the extremely high accuracy of the atomic clock has allowed the time dilation effect predicted by Special Relativity to be verified.

A more extreme (but hypothetical) example is the case of two twins: one remains on earth, the other journeys at a high speed (approaching the speed of light) to a distant star and back. Upon returning, the moving twin will have aged less than the twin who stayed on earth. Although this is not a simple situation, since accelerations are necessarily involved in the return journey, detailed analysis shows that Special Relativity gives the right answer for the difference in age.

Relativistic mass


Later in 1905, Einstein published a paper which shows that Newton's second law (F = ma) applies to any object, travelling at any speed v, provided its usual mass (called the rest mass, if measured when the object is stationary) is replaced by a relativistic mass given by:

 
relativistic mass = (gamma) (rest mass)

 
Since gamma > 1, there is a relativistic increase in mass. Therefore, if a constant force F is applied to a stationary object, it initially accelerates at a constant rate a = F/m0 (where m0 is its rest mass) but as the speed v approaches c , gamma becomes significantly larger than unity, the relativistic mass m significantly exceeds m0 and the rate of acceleration (a = F/m) decreases. In fact, the acceleration tends towards zero as v approaches c : no material object can travel at or above the speed of light (in vacuum). At high speeds, the work done by the force F goes into increasing the relativistic mass, rather than the speed. In other words, energy provided by the force is converted into mass. Einstein introduced the concept of the total energy E of an object

E = m c^2 = (gamma) m0 c^2 = K + m0 c^2

as being the sum of its kinetic energy K and its rest energy E0 = m0 c^2 . From this equation, it is easy to show that the correct general formula for kinetic energy is:

K = (gamma - 1) m0 c^2


rather than the classical expression: K = (1/2) m0 c^2 . However, Einstein's general formula is consistent with the classical expression, since for v<<c we can use the binomial theorem:


(1+x)^n = 1 + n x + (1/2)n(n-1) x^2 + ... = 1 + n x (approximately) if x<<1

 
with x = -v^2/c^2 and n = -1/2 , so that gamma = (1+x)^n , giving

 
K = (1 + nx - 1) m0 c^2 = (nx) m0 c^2 = (-1/2) (-v^2/c^2) m0 c^2 = (1/2) mo v^2

For v<<c, Special Relativity gives the same result as Classical Physics, an example of the Correspondence Principle which states that a new scientific theory must give the same predictions as an older theory under conditions in which the older theory has already been found to be correct.


One situation in which speeds comparable to c are routinely achieved is in the acceleration of charged particles, for example electrons in a TV tube, oscilloscope or electron microscope, or other particles in a nuclear accelerator. The particles (charge q) may be accelerated via an electrostatic field, by applying a potential U to an accelerating electrode. The gain in kinetic energy of a particle is then equal to its loss in potential energy: K = - q U . For the electrons in color-TV tube, q = -e = -1.6E-19 Coulomb, m0 = 9.11E-31 kg and U = +20,000 volts, giving K = 3.2E-15 Joules = (gamma - 1) m0 c^2, so that gamma = 1.04 and v = 0.27 c . The electron-optic design of the tube must take into account the relativistic mass increase, and the fact that such designs work as expected is further evidence for the the accuracy of the Special Theory.

 
The conversion of energy into mass leads to the concept that mass and energy are somewhat equivalent, and that it is actually the total which is conserved. The conservation of mass-energy therefore replaces our previous idea of the separate conservation of these two quantities. The reverse process, conversion of mass into energy, is also possible. For example, a star like our sun converts hydrogen into helium and heavier elements within its core, via a nuclear reaction. The products of this reaction have slightly less mass than the original hydrogen and this difference in mass (Dm) accounts for the radiant energy (E = Dm c^2 = 4.0E16 J/s) liberated. The same principle applies to nuclear reactors and nuclear weapons, and even to the energy liberated in chemical reactions (where the change in mass is too small to be measured).

 The math in the special theory wasn't too hard was it?  :roll:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Thumpalumpacus on August 30, 2013, 02:00:28 AM
Quote from: "josephpalazzo"And who says I'm treating them equally??? Before writing stupidities, use your head, if you have one!!!

You drew the equivalence, not me.:

Quote from: "josephpalazzo"I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who believe in unacceptable religious beliefs, like vaginal mutilation.

Thinking that the two issues merit the same treatment is silly.  Own your words, understand that you used hyperbole (by way of implicit comparison) in a stupid fashion, and know that others here read the language for meaning.  

Quote from: "josephpalazzo"Don't thank me, you're the idiot who blurped some idiocy regarding my post. Next time, mind your own business if you can't make some intelligent comment. You're a waste.

Your opinion of me is none of my business, and your advice none of my interest.  In the meantime, be sure you don't once more draw an equivalence between genocide and an incorrect comment, because it makes you look like someone who cannot tell the difference between a mutilated clitoris and a shitpost.


Don't like my opinion?  There now, pobrecito, you'll live[/backpat]
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Rob4you on August 30, 2013, 02:23:26 AM
Quote from: "Solitary"Why Witch Sabrina Looks Thinner While Riding On Her Broom? :evil:

You really shouldn't question Witch Sabrina figure, because well... she's a witch so she can do magic, and the least thing you'd want is to anger her and then awake to find out that you've become a frog and now are in her pot!  :shock:

 [-X
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on August 30, 2013, 04:08:40 AM
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on August 30, 2013, 05:28:22 AM
Quote from: "Thumpalumpacus"
Quote from: "josephpalazzo"And who says I'm treating them equally??? Before writing stupidities, use your head, if you have one!!!

You drew the equivalence, not me.:

Quote from: "josephpalazzo"I don't believe to be nice to people who are posting erroneous information. No more that I don't believe to be nice to people who believe in unacceptable religious beliefs, like vaginal mutilation.

Thinking that the two issues merit the same treatment is silly.  Own your words, understand that you used hyperbole (by way of implicit comparison) in a stupid fashion, and know that others here read the language for meaning.  

Quote from: "josephpalazzo"Don't thank me, you're the idiot who blurped some idiocy regarding my post. Next time, mind your own business if you can't make some intelligent comment. You're a waste.

Your opinion of me is none of my business, and your advice none of my interest.  In the meantime, be sure you don't once more draw an equivalence between genocide and an incorrect comment, because it makes you look like someone who cannot tell the difference between a mutilated clitoris and a shitpost.


Don't like my opinion?  There now, pobrecito, you'll live[/backpat]

Again, which part of "looking at the root causes" don't you understand? When I was comparing I wasn't talking about treatment, as vaginal mutilation is a criminal offense, and that would entail going to the police and get that criminal arrested. If you can't comprehend that my comparison was based on the root cause - that is, ignorance - then blame your limited IQ. And from now on, you are on my ignore list.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 11:38:15 AM
Quote from: "Rob4you"
Quote from: "Solitary"Why Witch Sabrina Looks Thinner While Riding On Her Broom? :evil:

You really shouldn't question Witch Sabrina figure, because well... she's a witch so she can do magic, and the least thing you'd want is to anger her and then awake to find out that you've become a frog and now are in her pot!  :shock:

 [-X

Witch Sabrina likes me she wouldn't do that. (//http://i.imgur.com/UcakxZu.gif)  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: WitchSabrina on August 30, 2013, 01:23:58 PM
:rollin:
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 30, 2013, 01:37:42 PM
Quote from: "Jason78"
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?

Kind of what he does, I asked him to insult me with wit and he plagiarized Shakespeare. Nothing wrong with copy and paste as long as you're citing the source and not attempting to claim it as your own.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 02:02:18 PM
Quote from: "Icarus"
Quote from: "Jason78"
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?

Kind of what he does, I asked him to insult me with wit and he plagiarized Shakespeare. Nothing wrong with copy and paste as long as you're citing the source and not attempting to claim it as your own.

If it was that obvious I didn't write it myself, how is that plagiarizing?  :P   I really did want to insult you with my own words, but the sad truth is you wouldn't have understood me.  :lol:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 02:05:13 PM
Quote from: "Jason78"
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?


If JosephPalazzo can do it so can I.  :lol:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 02:13:33 PM
Quote from: "Jason78"
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?


How can I explain math in my own words when it requires abstract symbols? :roll:  

How about like this without complicating everything like JosephPallazzo does with many formulas that don't show the gist of the theory: Guv=8pituv.  :rollin:  :rollin:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 30, 2013, 02:17:37 PM
Quote from: "Solitary"If it was that obvious I didn't write it myself, how is that plagiarizing?  :P   I really did want to insult you with my own words, but the sad truth is you wouldn't have understood me.  :lol:  Solitary

Really? I have to explain what constitutes plagiarism to an adult? Fine, plagiarism is anything where the author is taking credit for something they did not write. To avoid plagiarism you must cite the source of the quote and show the start and end of said quote. This is taught to every high school student at the start of each course. It's also explained every year, in every course in every university.

Your explanation of why you plagiarized Shakespeare falls short because the quote isn't in modern English. If you think I would understand that better, than how you were planning on insulting me? Were you planning on insulting me in German? French? Swahili?

I expect these kind of responses from teenagers who don't know any better and think they're super geniuses.

If you didn't mean to be intellectually dishonest and weren't trying to sound smarter than you actually are, you should have taken what I said for what it is (not an insult but trying to help someone who doesn't understand intellectual dishonesty). This will help you improve your arguments and quality of posts. If you continue to copy and paste without citing, you've just proven that you are willfully trying to be dishonest.


Quote from: "Solitary"How can I explain math in my own words when it requires abstract symbols?

Easily, when I explain enzyme mechanics I don't have to use symbols or highly complex terms. An individuals understanding of a topic is measured in how well they can explain it to a layman using their own words.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 02:47:10 PM
Quote from: "Icarus"
Quote from: "Solitary"If it was that obvious I didn't write it myself, how is that plagiarizing?  :P   I really did want to insult you with my own words, but the sad truth is you wouldn't have understood me.  :lol:  Solitary

Really? I have to explain what constitutes plagiarism to an adult? Fine, plagiarism is anything where the author is taking credit for something they did not write. To avoid plagiarism you must cite the source of the quote and show the start and end of said quote. This is taught to every high school student at the start of each course. It's also explained every year, in every course in every university.

Your explanation of why you plagiarized Shakespeare falls short because the quote isn't in modern English. If you think I would understand that better, than how you were planning on insulting me? Were you planning on insulting me in German? French? Swahili?

I expect these kind of responses from teenagers who don't know any better and think they're super geniuses.

If you didn't mean to be intellectually dishonest and weren't trying to sound smarter than you actually are, you should have taken what I said for what it is (not an insult but trying to help someone who doesn't understand intellectual dishonesty). This will help you improve your arguments and quality of posts. If you continue to copy and paste without citing, you've just proven that you are willfully trying to be dishonest.


Quote from: "Solitary"How can I explain math in my own words when it requires abstract symbols?

Easily, when I explain enzyme mechanics I don't have to use symbols or highly complex terms. An individuals understanding of a topic is measured in how well they can explain it to a layman using their own words.

And likewise JosephPallazzo should be able to explain the Special Theory of Relativity in layman's terms.
It's amazing how many people think that helping me when they don't understand what I have written or point out that I don't put something in quotes when it is obviously not my quote is not an insult. There are a few intellectual snobs here that think they know it all and project on to me their intellectual superiority by name calling or being pedantic ass holes apenaaier. "Stop het in je nauwe gaatje droogkloot! Hoed je rotssmoil! " Actually those are in my own words even if it does have quotation marks. lul :lol:  Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 30, 2013, 03:12:13 PM
Quote from: "Solitary"And likewise JosephPallazzo should be able to explain the Special Theory of Relativity in layman's terms.
It's amazing how many people think that helping me when they don't understand what I have written or point out that I don't put something in quotes when it is obviously not my quote is not an insult. There are a few intellectual snobs here that think they know it all and project on to me their intellectual superiority by name calling or being pedantic ass holes apenaaier. "Stop het in je nauwe gaatje droogkloot! Hoed je rotssmoil! " Actually those are in my own words even if it does have quotation marks. lul :lol:  Solitary

The awesome thing is you actually did learn something. You didn't know what intellectual dishonesty was and now you do! You can't talk about special relativity, then bitch and call people intellectual snobs when they want you to cite your source instead of just an easy copy paste. If the topic was crayon colour, you might have a point. If you did understand special relativity, that would make you an intellectual snob by proxy. What kind of non-intellectual can explain special relativity off the top of their head?

I see that you didn't really address anything in my post but are attempting to deflect by misspelling Dutch. The quote should read, "Stop het in je nauwe gaatje droogkloot! Hoed je rotssmoel!" Those aren't your own words (unless you're just really bad with Dutch) and they're not terribly witty.

You've now proven that you're willfully attempting to be dishonest. That didn't take very long.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on August 30, 2013, 04:45:42 PM
Quote from: "Solitary"
QuoteEven dummies can understand an "explanation" that doesn't really explain the theory.


 :-k  #-o  Lets see, an explanation of the special theory of relativity doesn't really explain it if it doesn't have math. Makes sense to me.  8-)  Thanks! Does this mean if someone can't explain the special theory of relativity in a way that a dummy can understand it they are smarter than a dummy?
No, it just means that you can't explain math (which is what SR is) without using math.  And you can't understand math if you don't understand math.

No matter how many non-mathematical "explanations" of SR you can find, they don't actually explain SR, they just give you something that makes you think that you understand something that you don't actually understand.  (Christians used to think that they understood lightning - it was something God did.  It was an explanation, but it was about as close to reality as a non-mathematical "explanation" of SR is.)  It's like the "explanation" of e=mc[sup:1pouv1uc]2[/sup:1pouv1uc] that you posted.  It explains something, but it doesn't explain e=mc[sup:1pouv1uc]2[/sup:1pouv1uc].  It just claims that it does.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 30, 2013, 11:45:57 PM
Quote from: "Colanth"
Quote from: "Solitary"
QuoteEven dummies can understand an "explanation" that doesn't really explain the theory.


 :-k  #-o  Lets see, an explanation of the special theory of relativity doesn't really explain it if it doesn't have math. Makes sense to me.  8-)  Thanks! Does this mean if someone can't explain the special theory of relativity in a way that a dummy can understand it they are smarter than a dummy?
No, it just means that you can't explain math (which is what SR is) without using math.  And you can't understand math if you don't understand math.

No matter how many non-mathematical "explanations" of SR you can find, they don't actually explain SR, they just give you something that makes you think that you understand something that you don't actually understand.  (Christians used to think that they understood lightning - it was something God did.  It was an explanation, but it was about as close to reality as a non-mathematical "explanation" of SR is.)  It's like the "explanation" of e=mc[sup:1tk09dvh]2[/sup:1tk09dvh] that you posted.  It explains something, but it doesn't explain e=mc[sup:1tk09dvh]2[/sup:1tk09dvh].  It just claims that it does.


No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.  E=MC squared is a math formula and doesn't explain what it means without an explanation either. Just because one knows the math doesn't mean they understand what it actually is saying. Do you know what n squared plus n divided by 2 = means and understand if it isn't explained? Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on August 31, 2013, 06:14:52 AM
Quote from: "Solitary"If it was that obvious I didn't write it myself, how is that plagiarizing?  :P

It's not always obvious.  Yet you post it as if it was your own words and fail to attribute a source.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on August 31, 2013, 06:24:09 AM
Quote from: "Solitary"
Quote from: "Jason78"
Quote from: "Solitary"The math in the special theory wasn't too hard was it?  :roll:  Solitary

You've copied and pasted that from //http://web.pdx.edu/~egertonr/ph311-12/relativ.htm.  Anybody can do that.

Care to explain that math in your own words?


How can I explain math in my own words when it requires abstract symbols? :roll:  

How about like this without complicating everything like JosephPallazzo does with many formulas that don't show the gist of the theory: Guv=8pituv.  :rollin:  :rollin:  Solitary

Those abstract symbols actually mean something!

Those formulas are the core of physics.   Instead of moaning about how hard maths is, why not actually try applying it?  Get a spreadsheet, feed in the formula for the lorentz factor and play with the numbers.  Try and get a feel for what these formulas mean, and maybe they'll stop looking like abstract symbols and end up actually meaning something to you.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 31, 2013, 10:36:59 AM
Quote from: "Solitary"No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.  E=MC squared is a math formula and doesn't explain what it means without an explanation either. Just because one knows the math doesn't mean they understand what it actually is saying. Do you know what n squared plus n divided by 2 = means and understand if it isn't explained? Solitary

Energy = Mass x Speed of light[sup:1jqun6u9]2[/sup:1jqun6u9] and the other less know version  M = (E[sub:1jqun6u9]0[/sub:1jqun6u9] + pV[sub:1jqun6u9]0[/sub:1jqun6u9])/c[sup:1jqun6u9]2[/sup:1jqun6u9] show the relationship of energy and mass in a system. The actual meaning of the symbols is self evident to anyone who's done any calculations regarding thermodynamics in a system (or other energy - system calculations). As the case with special relativity, all the symbols are known and understood by those who actually have to use the equations. Your example is terrible because you aren't defining n, thus suggesting the symbols in special relativity are not defined (which they are).
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 31, 2013, 01:08:31 PM
Quote from: "Icarus"
Quote from: "Solitary"No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.  E=MC squared is a math formula and doesn't explain what it means without an explanation either. Just because one knows the math doesn't mean they understand what it actually is saying. Do you know what n squared plus n divided by 2 = means and understand if it isn't explained? Solitary

Energy = Mass x Speed of light[sup:i6508z30]2[/sup:i6508z30] and the other less know version  M = (E[sub:i6508z30]0[/sub:i6508z30] + pV[sub:i6508z30]0[/sub:i6508z30])/c[sup:i6508z30]2[/sup:i6508z30] show the relationship of energy and mass in a system. The actual meaning of the symbols is self evident to anyone who's done any calculations regarding thermodynamics in a system (or other energy - system calculations). As the case with special relativity, all the symbols are known and understood by those who actually have to use the equations. Your example is terrible because you aren't defining n, thus suggesting the symbols in special relativity are not defined (which they are).

n can be any number by definition. I had a mathematics teacher answer what this means at this same forum when I was here originally. Calculate it with any number you want and the answer is obvious. Like you said:
QuoteThe actual meaning of the symbols is self evident to anyone who's done any calculations
Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 31, 2013, 01:33:16 PM
Quote from: "Solitary"n can be any number by definition. I had a mathematics teacher answer what this means at this same forum when I was here originally. Calculate it with any number you want and the answer is obvious. Like you said:
QuoteThe actual meaning of the symbols is self evident to anyone who's done any calculations
Solitary

Well yes, but without knowing n before you use the calculation you can't possibly understand what it is you're trying to calculate. In reference to my quote, when you're learning how to do the calculations you're also learning the context of the calculations. Without context math is, for all practical purposes, useless.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on August 31, 2013, 01:56:32 PM
Quote from: "Icarus"
Quote from: "Solitary"n can be any number by definition. I had a mathematics teacher answer what this means at this same forum when I was here originally. Calculate it with any number you want and the answer is obvious. Like you said:
QuoteThe actual meaning of the symbols is self evident to anyone who's done any calculations
Solitary

Well yes, but without knowing n before you use the calculation you can't possibly understand what it is you're trying to calculate. In reference to my quote, when you're learning how to do the calculations you're also learning the context of the calculations. Without context math is, for all practical purposes, useless.

Please explain how the mathematics teacher could if what you say is true. Take any natural number you want and replace n with that number and calculate. If you start with one and work your way up the answer is obvious. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Icarus on August 31, 2013, 02:10:48 PM
Quote from: "Solitary"Please explain how the mathematics teacher could if what you say is true. Take any natural number you want and replace n with that number and calculate. If you start with one and work your way up the answer is obvious. Solitary

If what I'm saying is true a mathematics teacher could do that easily. The problem is context, if I gave a mathematics teacher this equation: [P+a(n/v)[sup:117df7gi]2[/sup:117df7gi]]((V/n)-b) = RT (Van Der Waals equation)

The mathematics teacher would look at the formula and be stumped because (lets assume) he doesn't understand the context of the equation. He could spend any amount of time replacing values with different numbers but he would never discover how to use the formula without context.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on September 02, 2013, 07:59:24 PM
Quote from: "Solitary"No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.
Since the theory IS math, that's not true.  1 + 1 = 2 completely and sufficiently explains 1 + 1 = 2.

QuoteE=MC squared is a math formula and doesn't explain what it means without an explanation either.
Unless you understand what E m and c are, in which case it does.

I'm not talking about a "pop-sci" "explanation" for the masses (which is usually incorrect, insufficient and explains nothing), but an explanation that mathematicians can understand.  Anything else is like explaining a French pun to someone who doesn't speak French.  You can explain the words, but that doesn't explain why they're funny.  And by the time you get to why they're funny, no one's listening any more.

Sure you can "explain" SR without math.  But it's not complete, it's not sufficient and it's not accurate.  "That blue fish floating above the ground" doesn't actually "explain" what a fish swimming under water is, but that's closer than most verbal explanations of SR (or GR).

QuoteJust because one knows the math doesn't mean they understand what it actually is saying.
Well ... "knowing the math" MEANS "understanding what it's saying".  Knowing how to reduce a formula isn't knowing the math, it's knowing some mechanical operations.

QuoteDo you know what n squared plus n divided by 2 = means and understand if it isn't explained?
In no context?  Of course not.  You don't know what "Red" means out of context either.  But "SR" is its own context.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on September 02, 2013, 08:06:42 PM
Quote from: "Solitary"If you start with one and work your way up the answer is obvious.
The answer is obvious in context.  Unless you're discussing triangular numbers (which you probably had in that class), the answer is, at best, ambiguous.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on September 02, 2013, 10:43:22 PM
Quote from: "Colanth"
Quote from: "Solitary"No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.
Since the theory IS math, that's not true.  1 + 1 = 2 completely and sufficiently explains 1 + 1 = 2.

So 1 apple + 1 apple is the same as 1 apple +1 pear?

QuoteE=MC squared is a math formula and doesn't explain what it means without an explanation either.
Unless you understand what E m and c are, in which case it does.

But that's my point, unless you are explained to what E m and c are you have no idea what it means.

I'm not talking about a "pop-sci" "explanation" for the masses (which is usually incorrect, insufficient and explains nothing), but an explanation that mathematicians can understand.  Anything else is like explaining a French pun to someone who doesn't speak French.  You can explain the words, but that doesn't explain why they're funny.  And by the time you get to why they're funny, no one's listening any more.

Sure you can "explain" SR without math.  But it's not complete, it's not sufficient and it's not accurate.  "That blue fish floating above the ground" doesn't actually "explain" what a fish swimming under water is, but that's closer than most verbal explanations of SR (or GR).

Explain how it is not complete in order to understand what the theory is about? I know red is a certain frequency of electromagnetic waves without the math.

QuoteJust because one knows the math doesn't mean they understand what it actually is saying.
Well ... "knowing the math" MEANS "understanding what it's saying".  Knowing how to reduce a formula isn't knowing the math, it's knowing some mechanical operations.

Again, you know the math for n squared + n divided by 2 is, but do you know what it means?

It's not out of context if you can provide the answer for what it means which you can.

The answer is any natural number for n gives you the addition of all the numbers up to n using that formula. Until this is explained or calculated you have no idea what it is saying. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Colanth on September 03, 2013, 12:34:43 AM
Quote from: "Solitary"
Quote from: "Colanth"
Quote from: "Solitary"No matter how many mathematical "explanations" of SR you can find, they don't actually explain the Special theory either.
Since the theory IS math, that's not true.  1 + 1 = 2 completely and sufficiently explains 1 + 1 = 2.

So 1 apple + 1 apple is the same as 1 apple +1 pear?
No, that just demonstrates a lack of understanding of arithmetic (or an oversupply of wiseassery).

Quote
Quote
QuoteE=MC squared is a math formula and doesn't explain what it means without an explanation either.
Unless you understand what E m and c are, in which case it does.

But that's my point, unless you are explained to what E m and c are you have no idea what it means.
Or unless you understand math and physics.

Again, there's a difference between a complete and sufficient explanation (and don't confuse the two - complete and sufficient are completely different), and a pop-science "explanation" that doesn't actually explain anything, but it makes those too lazy or too stupid to actually learn enough to understand the subject think that they understand it.

QuoteSure you can "explain" SR without math.  But it's not complete, it's not sufficient and it's not accurate.  "That blue fish floating above the ground" doesn't actually "explain" what a fish swimming under water is, but that's closer than most verbal explanations of SR (or GR).

Explain how it is not complete in order to understand what the theory is about? I know red is a certain frequency of electromagnetic waves without the math.
Now you're talking about linguistics, not physics.  "Red" is DEFINED as the name we give to a certain band of electromagnetic frequencies.  So you understand the definition.

QuoteAgain, you know the math for n squared + n divided by 2 is, but do you know what it means?
It doesn't MEAN anything.  IT COULD BE referring to triangular numbers.  But it could also be referring to other things.  Out of context it's meaningless.

QuoteIt's not out of context if you can provide the answer for what it means which you can.
It's totally out of context.  (Evidently you don't understand the concept of "context".)

QuoteThe answer is any natural number for n gives you the addition of all the numbers up to n using that formula. Until this is explained or calculated you have no idea what it is saying.
It's actually "the sum" not "the addition" - and that description, "the sum of all integers from 1 to n", is math.  "All numbers up to n" gives you the sum of an infinite number of numbers, since "number" isn't limited to integers.  Describing an upper-case sigma, with an n on top, a k to the right and "k=1" on the bottom won't really tell you anything, but that's what the words are actually saying.  So you're just describing a formula in words.

SR is a special case of GR, and GR isn't simple enough to completely and sufficiently "describe" without using math.

I can describe beef stew without using genetics, but I can't fully and sufficiently describe "cow" without using genetics.  (Almost any "word" definition of "cow" that's not self-referential is ambiguous.)

(Oh, and it would make responding to you a lot easier if you used the quote tags properly.  Coloring text doesn't put quote tags around it.)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 03, 2013, 10:09:47 AM
There's something that isn't clear to me in this discussion. It's about what "actually contracted" means in this context. If there were a an absolute, fixed length dimension, then I could readily see how a length could be contracted with reference to that absolute, fixed length dimension and thus what "actually contracted" means ("actually contracted" meaning contracted with reference to a fixed, absolute length of a spatial dimension). But if there is no absolute, fixed length dimension that is a reference, then what length is being referenced to say that a contraction is actual?

I am not trying to claim that people are mistaken in saying that such a contraction is actual; what I'm wondering is if what may be going on here is that different people mean different things when they use the term "actual" in this context. I ask the above question to see if it may help ferret out any such differences in conception of what an "actual contraction of length" means, if there are any such differences.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 03, 2013, 11:23:26 AM
Quote from: "entropy"There's something that isn't clear to me in this discussion. It's about what "actually contracted" means in this context. If there were a an absolute, fixed length dimension, then I could readily see how a length could be contracted with reference to that absolute, fixed length dimension and thus what "actually contracted" means ("actually contracted" meaning contracted with reference to a fixed, absolute length of a spatial dimension). But if there is no absolute, fixed length dimension that is a reference, then what length is being referenced to say that a contraction is actual?

I am not trying to claim that people are mistaken in saying that such a contraction is actual; what I'm wondering is if what may be going on here is that different people mean different things when they use the term "actual" in this context. I ask the above question to see if it may help ferret out any such differences in conception of what an "actual contraction of length" means, if there are any such differences.

The best way to figure out things in SR is with graphics. You can represent one observer in a t-x graph, and a second one in a t' - x' axis.

(//http://i243.photobucket.com/albums/ff277/josephpalazzo/lengthcontraction.jpg) (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html)

In the case of length contraction, consider the ends of a meter stick that stand initially at the origin d(0,0) and at e(0,L). It is at rest in the unprimed frame of reference. And the two parallel lines in red indicate this. The dash line at 45° represents the speed of light ( t = x). The moving observer in the primed frame of reference will see a different meter stick. The moving observer will measure the meter stick along a synchronous time, which is the x'-axis, or t=vx, which will be the points d and f. But remember that df is really the proper time, a Lorentz invariant. What is the length that the moving observer measures? To find that, we must locate the x'-coordinate of the point f((0', L').

(1) t'[sup:1c2hvwb9]2[/sup:1c2hvwb9] – x'[sup:1c2hvwb9]2[/sup:1c2hvwb9]  =  t[sup:1c2hvwb9]2[/sup:1c2hvwb9] – x[sup:1c2hvwb9]2[/sup:1c2hvwb9]

Substituting,
(2) (0')[sup:1c2hvwb9]2[/sup:1c2hvwb9] – L'[sup:1c2hvwb9]2[/sup:1c2hvwb9] =  (vx)[sup:1c2hvwb9]2[/sup:1c2hvwb9] – x[sup:1c2hvwb9]2[/sup:1c2hvwb9]

(3) – L'[sup:1c2hvwb9]2[/sup:1c2hvwb9] =  v[sup:1c2hvwb9]2[/sup:1c2hvwb9]L[sup:1c2hvwb9]2[/sup:1c2hvwb9] – L[sup:1c2hvwb9]2[/sup:1c2hvwb9]
or L'[sup:1c2hvwb9]2[/sup:1c2hvwb9] =  – v[sup:1c2hvwb9]2[/sup:1c2hvwb9]L[sup:1c2hvwb9]2[/sup:1c2hvwb9]  +  L[sup:1c2hvwb9]2[/sup:1c2hvwb9]
                                                               
(4) L'[sup:1c2hvwb9]2[/sup:1c2hvwb9] =  (– v[sup:1c2hvwb9]2[/sup:1c2hvwb9]  +  1)L[sup:1c2hvwb9]2[/sup:1c2hvwb9]
 
(5) L'[sup:1c2hvwb9]2[/sup:1c2hvwb9] =  ( 1  –   v[sup:1c2hvwb9]2[/sup:1c2hvwb9] )L[sup:1c2hvwb9]2[/sup:1c2hvwb9]

Taking the square root and putting c back into the equation,
                                     
(6) moving ruler  =  stationary ruler (1  –  v[sup:1c2hvwb9]2[/sup:1c2hvwb9]/c[sup:1c2hvwb9]2[/sup:1c2hvwb9])[sup:1c2hvwb9]1/2[/sup:1c2hvwb9]
                                                               
We see that a moving meter will shrink.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 03, 2013, 12:19:36 PM
Quote from: "josephpalazzo"
Quote from: "entropy"There's something that isn't clear to me in this discussion. It's about what "actually contracted" means in this context. If there were a an absolute, fixed length dimension, then I could readily see how a length could be contracted with reference to that absolute, fixed length dimension and thus what "actually contracted" means ("actually contracted" meaning contracted with reference to a fixed, absolute length of a spatial dimension). But if there is no absolute, fixed length dimension that is a reference, then what length is being referenced to say that a contraction is actual?

I am not trying to claim that people are mistaken in saying that such a contraction is actual; what I'm wondering is if what may be going on here is that different people mean different things when they use the term "actual" in this context. I ask the above question to see if it may help ferret out any such differences in conception of what an "actual contraction of length" means, if there are any such differences.

The best way to figure out things in SR is with graphics. You can represent one observer in a t-x graph, and a second one in a t' - x' axis.

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html) ]

In the case of length contraction, consider the ends of a meter stick that stand initially at the origin d(0,0) and at e(0,L). It is at rest in the unprimed frame of reference. And the two parallel lines in red indicate this. The dash line at 45° represents the speed of light ( t = x). The moving observer in the primed frame of reference will see a different meter stick. The moving observer will measure the meter stick along a synchronous time, which is the x'-axis, or t=vx, which will be the points d and f. But remember that df is really the proper time, a Lorentz invariant. What is the length that the moving observer measures? To find that, we must locate the x'-coordinate of the point f((0', L').

(1) t'[sup:2n49rp3n]2[/sup:2n49rp3n] – x'[sup:2n49rp3n]2[/sup:2n49rp3n]  =  t[sup:2n49rp3n]2[/sup:2n49rp3n] – x[sup:2n49rp3n]2[/sup:2n49rp3n]

Substituting,
(2) (0')[sup:2n49rp3n]2[/sup:2n49rp3n] – L'[sup:2n49rp3n]2[/sup:2n49rp3n] =  (vx)[sup:2n49rp3n]2[/sup:2n49rp3n] – x[sup:2n49rp3n]2[/sup:2n49rp3n]

(3) – L'[sup:2n49rp3n]2[/sup:2n49rp3n] =  v[sup:2n49rp3n]2[/sup:2n49rp3n]L[sup:2n49rp3n]2[/sup:2n49rp3n] – L[sup:2n49rp3n]2[/sup:2n49rp3n]
or L'[sup:2n49rp3n]2[/sup:2n49rp3n] =  – v[sup:2n49rp3n]2[/sup:2n49rp3n]L[sup:2n49rp3n]2[/sup:2n49rp3n]  +  L[sup:2n49rp3n]2[/sup:2n49rp3n]
                                                               
(4) L'[sup:2n49rp3n]2[/sup:2n49rp3n] =  (– v[sup:2n49rp3n]2[/sup:2n49rp3n]  +  1)L[sup:2n49rp3n]2[/sup:2n49rp3n]
 
(5) L'[sup:2n49rp3n]2[/sup:2n49rp3n] =  ( 1  –   v[sup:2n49rp3n]2[/sup:2n49rp3n] )L[sup:2n49rp3n]2[/sup:2n49rp3n]

Taking the square root and putting c back into the equation,
                                     
(6) moving ruler  =  stationary ruler (1  –  v[sup:2n49rp3n]2[/sup:2n49rp3n]/c[sup:2n49rp3n]2[/sup:2n49rp3n])[sup:2n49rp3n]1/2[/sup:2n49rp3n]
                                                               
We see that a moving meter will shrink.

I think I follow that, but it still isn't clear to me why this implies that the contraction is "actual" unless the stationary ruler is taken to be "the preferred" reference frame in terms of measurement of length. In a sense, it appears you want to treat the stationary ruler as though it were a fixed, absolute reference frame for length in terms of determining whether or not the moving ruler has "actually" contracted. Is there some reason to treat the stationary ruler as being preferred with respect to measuring length over the moving ruler? To put it another way, it's seems like you are saying that with respect to the stationary ruler, the moving ruler is contracted, therefore the contraction is 'actual'. But from the reference frame of the moving ruler, it is not contracted, therefore couldn't it be just as validly claimed that with respect to the reference frame of the moving ruler that there is no 'actual" contraction?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on September 03, 2013, 01:15:06 PM
This might help explain it better, or not. :[youtube:1tm4qvgh]http://www.youtube.com/watch?v=rek7881OGRY[/youtube:1tm4qvgh]

As far as length contraction goes, the question is what is meant by a real physical
phenomenon.  Of course, objects are not really squeezed together in the sense that stress or strain forces could be measured.  But in three dimensions, length contraction might not even be apparent.

 Objects sometimes appear to be contracted, but only because they are rotated.  A sphere, for example, would appear to be rotated - not distorted to an ellipsoid.  Even after almost a century of STR, the subject of how moving bodies would appear if c = 100m/s remains controversial.

Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 03, 2013, 02:41:53 PM
Quote from: "entropy"
Quote from: "josephpalazzo"
Quote from: "entropy"There's something that isn't clear to me in this discussion. It's about what "actually contracted" means in this context. If there were a an absolute, fixed length dimension, then I could readily see how a length could be contracted with reference to that absolute, fixed length dimension and thus what "actually contracted" means ("actually contracted" meaning contracted with reference to a fixed, absolute length of a spatial dimension). But if there is no absolute, fixed length dimension that is a reference, then what length is being referenced to say that a contraction is actual?

I am not trying to claim that people are mistaken in saying that such a contraction is actual; what I'm wondering is if what may be going on here is that different people mean different things when they use the term "actual" in this context. I ask the above question to see if it may help ferret out any such differences in conception of what an "actual contraction of length" means, if there are any such differences.

The best way to figure out things in SR is with graphics. You can represent one observer in a t-x graph, and a second one in a t' - x' axis.

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html) ]

In the case of length contraction, consider the ends of a meter stick that stand initially at the origin d(0,0) and at e(0,L). It is at rest in the unprimed frame of reference. And the two parallel lines in red indicate this. The dash line at 45° represents the speed of light ( t = x). The moving observer in the primed frame of reference will see a different meter stick. The moving observer will measure the meter stick along a synchronous time, which is the x'-axis, or t=vx, which will be the points d and f. But remember that df is really the proper time, a Lorentz invariant. What is the length that the moving observer measures? To find that, we must locate the x'-coordinate of the point f((0', L').

(1) t'[sup:3i08t9nq]2[/sup:3i08t9nq] – x'[sup:3i08t9nq]2[/sup:3i08t9nq]  =  t[sup:3i08t9nq]2[/sup:3i08t9nq] – x[sup:3i08t9nq]2[/sup:3i08t9nq]

Substituting,
(2) (0')[sup:3i08t9nq]2[/sup:3i08t9nq] – L'[sup:3i08t9nq]2[/sup:3i08t9nq] =  (vx)[sup:3i08t9nq]2[/sup:3i08t9nq] – x[sup:3i08t9nq]2[/sup:3i08t9nq]

(3) – L'[sup:3i08t9nq]2[/sup:3i08t9nq] =  v[sup:3i08t9nq]2[/sup:3i08t9nq]L[sup:3i08t9nq]2[/sup:3i08t9nq] – L[sup:3i08t9nq]2[/sup:3i08t9nq]
or L'[sup:3i08t9nq]2[/sup:3i08t9nq] =  – v[sup:3i08t9nq]2[/sup:3i08t9nq]L[sup:3i08t9nq]2[/sup:3i08t9nq]  +  L[sup:3i08t9nq]2[/sup:3i08t9nq]
                                                               
(4) L'[sup:3i08t9nq]2[/sup:3i08t9nq] =  (– v[sup:3i08t9nq]2[/sup:3i08t9nq]  +  1)L[sup:3i08t9nq]2[/sup:3i08t9nq]
 
(5) L'[sup:3i08t9nq]2[/sup:3i08t9nq] =  ( 1  –   v[sup:3i08t9nq]2[/sup:3i08t9nq] )L[sup:3i08t9nq]2[/sup:3i08t9nq]

Taking the square root and putting c back into the equation,
                                     
(6) moving ruler  =  stationary ruler (1  –  v[sup:3i08t9nq]2[/sup:3i08t9nq]/c[sup:3i08t9nq]2[/sup:3i08t9nq])[sup:3i08t9nq]1/2[/sup:3i08t9nq]
                                                               
We see that a moving meter will shrink.

I think I follow that, but it still isn't clear to me why this implies that the contraction is "actual" unless the stationary ruler is taken to be "the preferred" reference frame in terms of measurement of length. In a sense, it appears you want to treat the stationary ruler as though it were a fixed, absolute reference frame for length in terms of determining whether or not the moving ruler has "actually" contracted. Is there some reason to treat the stationary ruler as being preferred with respect to measuring length over the moving ruler? To put it another way, it's seems like you are saying that with respect to the stationary ruler, the moving ruler is contracted, therefore the contraction is 'actual'. But from the reference frame of the moving ruler, it is not contracted, therefore couldn't it be just as validly claimed that with respect to the reference frame of the moving ruler that there is no 'actual" contraction?

What the graphics says is:

The laws of nature should not depend on the coordinate system. So whether one chooses the coordinate x-t or the coordinate x'-t', or any other type of coordinate system for that matter, the laws of nature should be the same. So that explains equation (1) -- both see that the speed of light is constant, as required by the null result of the Michaelson-Morley experiment, and Maxwell's equations. The rest of the equations in the derivation just follow logically by the rules of math. Now, from equation (6) if you are stationary, your ruler doesn't contract. So in your frame, nothing happens. Now, you have to remember, there is also time dilation taking place. It's the combination of these two effects, that makes the speed of light constant for every observer.

Now in practice, you won't be able to measure that contraction: how do you measure the length of something which is moving away from you? However, time dilation can be measured in the half-life of cosmic muons as they come from outerspace, which differs from the half-life of muons produced in the lab. The difference is fully acounted by SR.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 03, 2013, 08:50:17 PM
Quote from: "josephpalazzo"What the graphics says is:

The laws of nature should not depend on the coordinate system. So whether one chooses the coordinate x-t or the coordinate x'-t', or any other type of coordinate system for that matter, the laws of nature should be the same. So that explains equation (1) -- both see that the speed of light is constant, as required by the null result of the Michaelson-Morley experiment, and Maxwell's equations. The rest of the equations in the derivation just follow logically by the rules of math. Now, from equation (6) if you are stationary, your ruler doesn't contract. So in your frame, nothing happens. Now, you have to remember, there is also time dilation taking place. It's the combination of these two effects, that makes the speed of light constant for every observer.

Now in practice, you won't be able to measure that contraction: how do you measure the length of something which is moving away from you? However, time dilation can be measured in the half-life of cosmic muons as they come from outerspace, which differs from the half-life of muons produced in the lab. The difference is fully acounted by SR.

Okay, that helped. It seems that the issue I'm zeroing in on depends on the designation of proper time - the time of the non-moving ruler, if I understand it right. I guess what I'm getting hung up on is probably a very common stumbling block - if neither ruler is accelerating, then why is one ruler designated as being the one with proper time. But I imagine that's an elementary issue you deal with quite often with students so I won't trouble you to ask about it. Thank you for taking the time to answer my questions.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 03, 2013, 09:10:08 PM
Quote from: "entropy"
Quote from: "josephpalazzo"What the graphics says is:

The laws of nature should not depend on the coordinate system. So whether one chooses the coordinate x-t or the coordinate x'-t', or any other type of coordinate system for that matter, the laws of nature should be the same. So that explains equation (1) -- both see that the speed of light is constant, as required by the null result of the Michaelson-Morley experiment, and Maxwell's equations. The rest of the equations in the derivation just follow logically by the rules of math. Now, from equation (6) if you are stationary, your ruler doesn't contract. So in your frame, nothing happens. Now, you have to remember, there is also time dilation taking place. It's the combination of these two effects, that makes the speed of light constant for every observer.

Now in practice, you won't be able to measure that contraction: how do you measure the length of something which is moving away from you? However, time dilation can be measured in the half-life of cosmic muons as they come from outerspace, which differs from the half-life of muons produced in the lab. The difference is fully acounted by SR.

Okay, that helped. It seems that the issue I'm zeroing in on depends on the designation of proper time - the time of the non-moving ruler, if I understand it right. I guess what I'm getting hung up on is probably a very common stumbling block - if neither ruler is accelerating, then why is one ruler designated as being the one with proper time. But I imagine that's an elementary issue you deal with quite often with students so I won't trouble you to ask about it. Thank you for taking the time to answer my questions.

There is an easy trick to remember who is measuring the proper time: it's always the observer who measures two events with one clock.

(//http://i243.photobucket.com/albums/ff277/josephpalazzo/lengthcontraction.jpg) (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html)

In coordinate t-x, in which the ruler is at rest, the observer needs two clocks: one at d(0,0), and a second one at e(0,L). The observer in t' - x' can use one clock since the ruler is moving wrt to his frame. He can wait from one end to pass in front of him, at which time he sets t' = 0, and then when the ruler's other end passes in front of him, he measures t', and so this is the proper time in this situation.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 03, 2013, 11:11:44 PM
Quote from: "josephpalazzo"
Quote from: "entropy"Okay, that helped. It seems that the issue I'm zeroing in on depends on the designation of proper time - the time of the non-moving ruler, if I understand it right. I guess what I'm getting hung up on is probably a very common stumbling block - if neither ruler is accelerating, then why is one ruler designated as being the one with proper time. But I imagine that's an elementary issue you deal with quite often with students so I won't trouble you to ask about it. Thank you for taking the time to answer my questions.

There is an easy trick to remember who is measuring the proper time: it's always the observer who measures two events with one clock.

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html) ]

In coordinate t-x, in which the ruler is at rest, the observer needs two clocks: one at d(0,0), and a second one at e(0,L). The observer in t' - x' can use one clock since the ruler is moving wrt to his frame. He can wait from one end to pass in front of him, at which time he sets t' = 0, and then when the ruler's other end passes in front of him, he measures t', and so this is the proper time in this situation.

Since you have been nice enough to try to explain this to me, I'm going to be bold enough to ask what I imagine are basic questions that occur to a lot of people when they encounter these issues (or, worse, don't occur to most people because the answers are so obvious that most people see the answer and don't have questions):

Hypothesize that the whole universe is made up of only two rulers. Each can send light impulses toward the other and detect a reflection and measure the time it takes the light to be emitted and the reflection detected, so the rulers are able to determine that the displacement between them is increasing at a regular rate. Wouldn't it be arbitrary as to which ruler gets designated as "at rest" - which then determines which ruler's time is considered proper time? If it is arbitrary as to which gets designated as at rest, then wouldn't it be arbitrary as to which one is considered to have actually contracted?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Solitary on September 04, 2013, 02:05:09 AM
This post is getting really tiresome, so this is the last time I'll try to explain what actually happens in the real world we live in and not the world of mathematics with regards to the special theory of relativity that makes logical sense and is easy to understand without a bunch of mathematical equation to obscure everything.

Special relativity applies the Galilean relativity principle to electromagnetic theory. Since the speed of light is determined by basic equations of that theory, if the relativity principle is to hold, you can conclude that the speed of light must be the same for observers in any inertial frame, regardless of the velocity of the light's source. This is profoundly counter-intuitive, once one explores what it means. Three of the immediate consequences of the constancy of light's velocity are the relativity of simultaneity, length contraction (apparent shortening, in the direction of motion, of rapidly moving objects), and time dilation (apparent slowing down of fast-moving clocks).

I can explain an instance of the first phenomenon here, using an example first crafted by Einstein. Suppose a fast-moving train is passing a signal light on the ground. Just as the center of the car you are in passes the lamp, it emits a flash of red light. Since you know the speed of light is a fixed constant c in inertial frames, and you are in an inertial frame, you conclude that the flash of light arrives simultaneously at the back and the front of your train car. The two arrival events, for you, are simultaneous. But now consider how an observer standing next to the signal lamp on the ground views events.

 The light travels at the same speed c toward the back of the train and toward the front. But the train is moving, fast, forward. So the light will reach the rear of your car first, and then the forward-going light rays, having to catch up to the rapidly advancing front, will arrive some time later. That is: for the observer on the ground, the two events (light arrives at back of car; light arrives at front) are definitely not simultaneous.

And if the Special Principle of relativity is to be taken seriously, we must admit that neither observer's perspective is "correct"; judgment that two events in different locations are "simultaneous" is simply relative – relative to state of motion, or reference frame. (The other two surprising effects just mentioned can be deduced from similarly simple thought-experiments.

Anyone that disagrees it's OK with me because this makes sense to me and to say solid object actually contracts to one observer and not to another and vice versa is ridiculous unless you are talking about measurement. Solitary
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 04, 2013, 09:00:38 AM
Quote from: "Solitary"This post is getting really tiresome, so this is the last time I'll try to explain what actually happens in the real world we live in and not the world of mathematics with regards to the special theory of relativity that makes logical sense and is easy to understand without a bunch of mathematical equation to obscure everything.

Special relativity applies the Galilean relativity principle to electromagnetic theory. Since the speed of light is determined by basic equations of that theory, if the relativity principle is to hold, you can conclude that the speed of light must be the same for observers in any inertial frame, regardless of the velocity of the light's source. This is profoundly counter-intuitive, once one explores what it means. Three of the immediate consequences of the constancy of light's velocity are the relativity of simultaneity, length contraction (apparent shortening, in the direction of motion, of rapidly moving objects), and time dilation (apparent slowing down of fast-moving clocks).

I can explain an instance of the first phenomenon here, using an example first crafted by Einstein. Suppose a fast-moving train is passing a signal light on the ground. Just as the center of the car you are in passes the lamp, it emits a flash of red light. Since you know the speed of light is a fixed constant c in inertial frames, and you are in an inertial frame, you conclude that the flash of light arrives simultaneously at the back and the front of your train car. The two arrival events, for you, are simultaneous. But now consider how an observer standing next to the signal lamp on the ground views events.

 The light travels at the same speed c toward the back of the train and toward the front. But the train is moving, fast, forward. So the light will reach the rear of your car first, and then the forward-going light rays, having to catch up to the rapidly advancing front, will arrive some time later. That is: for the observer on the ground, the two events (light arrives at back of car; light arrives at front) are definitely not simultaneous.

And if the Special Principle of relativity is to be taken seriously, we must admit that neither observer's perspective is "correct"; judgment that two events in different locations are "simultaneous" is simply relative – relative to state of motion, or reference frame. (The other two surprising effects just mentioned can be deduced from similarly simple thought-experiments.

Anyone that disagrees it's OK with me because this makes sense to me and to say solid object actually contracts to one observer and not to another and vice versa is ridiculous unless you are talking about measurement. Solitary

There are one or two things you said that I might quibble with a bit, but the quibbles probably are more about how you chose to express certain notions than about the substance of what you were expressing.

I appreciate josephpalazzo taking the time to lay out the mathematics. It has helped me come to see that my questions seem to center on the issue of which object gets designated as "at rest" and therefore is said to have proper time for purposes of cranking through the equations of special relativity. I think his conversation with me has led me to realize that I don't understand on what basis the designation "at rest" is made.

In your discussion above about the two observers - one on a train and the other standing off to the side of the train - you posit the situation as the train being in motion. But doesn't that assume that the earth is at rest (and the observer standing "solidly" on the earth is also at rest)? To the observer on the train, relative to the train he is on, isn't he "at rest"? I don't get on what basis we take one observer to be at rest for purposes of the calculations. Is it a matter of determining something like momentum - e.g., that the train has momentum that the earth doesn't and so the train is said to be in motion and the earth "at rest"? If the determining factor isn't something like momentum, then it seems like designating the earth being at rest and the train in motion is just a consequence of our psychological impressions due to the relative size differences between the train and the earth.

Your explication above reminded me of the experiment Doppler did with a musician playing on note on a horn on a moving train. I'm not sure how tightly the Doppler experiment holds as an analogy, but it does seem like the interpretation of what Doppler showed in his experiment is similar to the situation with respect to special relativity and contraction. As the train approached Doppler, the pitch of the note was higher than it was for those who were riding on the train with the musician. In such a situation, does it make sense to say that the pitch was "actually" higher? Well, it was "actually" a higher pitch for those standing outside the train with the train approaching, but the pitch was not "actually" higher for those riding on the train with the musician. So in Doppler's case the "actually" is relative to the observer. What isn't evident to me yet is why the situation with the perception of length contraction isn't very much like that with Doppler's findings about what the observers on the train and off the train hear; that is, that the impression of contraction is relative to the observer and that there is no "actual" contraction taking place in an absolute sense - just like there is no absolute sense of which heard note was the "actual" note in Doppler's case.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 04, 2013, 09:37:21 AM
Quote from: "entropy"
Quote from: "josephpalazzo"
Quote from: "entropy"Okay, that helped. It seems that the issue I'm zeroing in on depends on the designation of proper time - the time of the non-moving ruler, if I understand it right. I guess what I'm getting hung up on is probably a very common stumbling block - if neither ruler is accelerating, then why is one ruler designated as being the one with proper time. But I imagine that's an elementary issue you deal with quite often with students so I won't trouble you to ask about it. Thank you for taking the time to answer my questions.

There is an easy trick to remember who is measuring the proper time: it's always the observer who measures two events with one clock.

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/lengthcontraction.jpg.html) ]

In coordinate t-x, in which the ruler is at rest, the observer needs two clocks: one at d(0,0), and a second one at e(0,L). The observer in t' - x' can use one clock since the ruler is moving wrt to his frame. He can wait from one end to pass in front of him, at which time he sets t' = 0, and then when the ruler's other end passes in front of him, he measures t', and so this is the proper time in this situation.

Since you have been nice enough to try to explain this to me, I'm going to be bold enough to ask what I imagine are basic questions that occur to a lot of people when they encounter these issues (or, worse, don't occur to most people because the answers are so obvious that most people see the answer and don't have questions):

Hypothesize that the whole universe is made up of only two rulers. Each can send light impulses toward the other and detect a reflection and measure the time it takes the light to be emitted and the reflection detected, so the rulers are able to determine that the displacement between them is increasing at a regular rate. Wouldn't it be arbitrary as to which ruler gets designated as "at rest" - which then determines which ruler's time is considered proper time? If it is arbitrary as to which gets designated as at rest, then wouldn't it be arbitrary as to which one is considered to have actually contracted?


Which frame is at rest and which one is moving is not determined by the rulers as such but by the observers. If the two observers are at rest with each other, there is no relativistic effect according to SR. Where are your observers wrt to the two rulers? Secondly, you need to determine which "events" your observers are considering. Are they measuring a time interval? Or a distance? Measuring a time interval and measuring a distance require to perform different experiments. Hence what will be labeled as the "events" will determine who is at rest and who is moving.

Now in your scenario as it is constructed, it seems that the rulers are at rest wrt each other, and since you didn't specify any observer, there is no effect of the SR kind.

However, you say that the displacement is increasing at a regular rate. This is analogous with galaxies moving away from each other. In this case, we are talking about General Relativity, not Special Relativity. This is a different ballgame. If you want clarification on SR, you should stick to scenarios in which SR effects take place.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: Jason78 on September 04, 2013, 10:11:18 AM
Quote from: "Solitary"This post is getting really tiresome

Really?

Crtl-C, Ctrl-V must really take it out of you. (//http://plato.stanford.edu/entries/spacetime-theories/notes.html)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 04, 2013, 11:33:08 AM
Quote from: "josephpalazzo"
Quote from: "entropy"Hypothesize that the whole universe is made up of only two rulers. Each can send light impulses toward the other and detect a reflection and measure the time it takes the light to be emitted and the reflection detected, so the rulers are able to determine that the displacement between them is increasing at a regular rate. Wouldn't it be arbitrary as to which ruler gets designated as "at rest" - which then determines which ruler's time is considered proper time? If it is arbitrary as to which gets designated as at rest, then wouldn't it be arbitrary as to which one is considered to have actually contracted?


Which frame is at rest and which one is moving is not determined by the rulers as such but by the observers. If the two observers are at rest with each other, there is no relativistic effect according to SR. Where are your observers wrt to the two rulers? Secondly, you need to determine which "events" your observers are considering. Are they measuring a time interval? Or a distance? Measuring a time interval and measuring a distance require to perform different experiments. Hence what will be labeled as the "events" will determine who is at rest and who is moving.

Now in your scenario as it is constructed, it seems that the rulers are at rest wrt each other, and since you didn't specify any observer, there is no effect of the SR kind.

However, you say that the displacement is increasing at a regular rate. This is analogous with galaxies moving away from each other. In this case, we are talking about General Relativity, not Special Relativity. This is a different ballgame. If you want clarification on SR, you should stick to scenarios in which SR effects take place.

I tried to keep the situation as simple as possible so I sort of fudged the "observer" part. I'll try to rectify that with another more carefully crafted hypothesis. I'm not sure what the ramifications are of your point about the differences in measuring time and distance, but I'll also try to see if I can deal with that in the reworked hypothesis.

Something I don't understand is why a regular rate of increasing displacement implies that the hypothetical involves the same factors as that which are causing the increasing displacement between distant galaxies to increase. If I understand it correctly, the increase in displacement between distant galaxies is caused by an expansion of spacetime between the the distant galaxies. If that is the case, I'm not sure why we would have to assume that the spacetime between the rulers in my hypothetical were in a situation where spacetime was expanding. I'll try to deal with that in the reworked hypothesis as well.

New hypothetical situation:

Imagine that there is a universe with a finite "sphere" of spacetime where there is no expansion or contraction of the spacetime "fabric" itself. The only other things (other than spacetime itself) in this universe are two rulers that have observers on them that have devices that can send out light and detect a reflection of the light and have a clock with which to measure how long it takes the light to travel from the time of emission to the time of detection of the reflected light. Each observer sends out a beam of light and measures the time it takes the beam to reflect off of the other ruler back to the detector - the time being that which each measures with their own clock. They use that time and the known speed of light to calculate the distance the light went. They do this measurement several times and each time they do it, the distance the light went is calculated to be more than the previous calculated distance. For measurements that are made at equal time intervals apart by their own clocks, the calculated distance the light travels increases the same amount.

For purposes of using the equations of special relativity to calculate contraction, how do we determine which ruler/observer is at rest? It doesn't seem like they can be at rest with respect to each other because the distance light travels between the two different ruler/observers is calculated to be increasing at a regular rate.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 04, 2013, 03:06:47 PM
Quote from: "entropy"New hypothetical situation:

Imagine that there is a universe with a finite "sphere" of spacetime where there is no expansion or contraction of the spacetime "fabric" itself. The only other things (other than spacetime itself) in this universe are two rulers that have observers on them that have devices that can send out light and detect a reflection of the light and have a clock with which to measure how long it takes the light to travel from the time of emission to the time of detection of the reflected light. Each observer sends out a beam of light and measures the time it takes the beam to reflect off of the other ruler back to the detector - the time being that which each measures with their own clock. They use that time and the known speed of light to calculate the distance the light went. They do this measurement several times and each time they do it, the distance the light went is calculated to be more than the previous calculated distance. For measurements that are made at equal time intervals apart by their own clocks, the calculated distance the light travels increases the same amount.

For purposes of using the equations of special relativity to calculate contraction, how do we determine which ruler/observer is at rest? It doesn't seem like they can be at rest with respect to each other because the distance light travels between the two different ruler/observers is calculated to be increasing at a regular rate.


The only way I can explain what's happening is on a graphic (sorry if my drawings are not up to par,  :-D )

(//http://i243.photobucket.com/albums/ff277/josephpalazzo/SR-movingaway.jpg) (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html)

The two blue lines would be the case if you and a distant object are at rest with each other, and a signal (in yellow) is sent back and forth. You can see that you would be receiving a signal at equal interval.

The axis in red represents the object moving away from you, and a signal (in green) is sent back and forth. You can see that the time elapsed between each signal is larger and larger.

Who said that a picture is worth a thousand words?  :P
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 04, 2013, 10:52:13 PM
Quote from: "josephpalazzo"
Quote from: "entropy"New hypothetical situation:

Imagine that there is a universe with a finite "sphere" of spacetime where there is no expansion or contraction of the spacetime "fabric" itself. The only other things (other than spacetime itself) in this universe are two rulers that have observers on them that have devices that can send out light and detect a reflection of the light and have a clock with which to measure how long it takes the light to travel from the time of emission to the time of detection of the reflected light. Each observer sends out a beam of light and measures the time it takes the beam to reflect off of the other ruler back to the detector - the time being that which each measures with their own clock. They use that time and the known speed of light to calculate the distance the light went. They do this measurement several times and each time they do it, the distance the light went is calculated to be more than the previous calculated distance. For measurements that are made at equal time intervals apart by their own clocks, the calculated distance the light travels increases the same amount.

For purposes of using the equations of special relativity to calculate contraction, how do we determine which ruler/observer is at rest? It doesn't seem like they can be at rest with respect to each other because the distance light travels between the two different ruler/observers is calculated to be increasing at a regular rate.


The only way I can explain what's happening is on a graphic (sorry if my drawings are not up to par,  :-D )

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html) ]

The two blue lines would be the case if you and a distant object are at rest with each other, and a signal (in yellow) is sent back and forth. You can see that you would be receiving a signal at equal interval.

The axis in red represents the object moving away from you, and a signal (in green) is sent back and forth. You can see that the time elapsed between each signal is larger and larger.

Who said that a picture is worth a thousand words?  :P

I do think I understand the graphic but I'm not sure how it answers my question. I'm probably either asking a nonsensical question or not expressing it clearly enough. Thanks for taking the time to try to help me figure it out, though.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 05, 2013, 10:27:13 AM
Quote from: "entropy"
Quote from: "josephpalazzo"
Quote from: "entropy"New hypothetical situation:

Imagine that there is a universe with a finite "sphere" of spacetime where there is no expansion or contraction of the spacetime "fabric" itself. The only other things (other than spacetime itself) in this universe are two rulers that have observers on them that have devices that can send out light and detect a reflection of the light and have a clock with which to measure how long it takes the light to travel from the time of emission to the time of detection of the reflected light. Each observer sends out a beam of light and measures the time it takes the beam to reflect off of the other ruler back to the detector - the time being that which each measures with their own clock. They use that time and the known speed of light to calculate the distance the light went. They do this measurement several times and each time they do it, the distance the light went is calculated to be more than the previous calculated distance. For measurements that are made at equal time intervals apart by their own clocks, the calculated distance the light travels increases the same amount.

For purposes of using the equations of special relativity to calculate contraction, how do we determine which ruler/observer is at rest? It doesn't seem like they can be at rest with respect to each other because the distance light travels between the two different ruler/observers is calculated to be increasing at a regular rate.


The only way I can explain what's happening is on a graphic (sorry if my drawings are not up to par,  :-D )

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html) ]

The two blue lines would be the case if you and a distant object are at rest with each other, and a signal (in yellow) is sent back and forth. You can see that you would be receiving a signal at equal interval.

The axis in red represents the object moving away from you, and a signal (in green) is sent back and forth. You can see that the time elapsed between each signal is larger and larger.

Who said that a picture is worth a thousand words?  :P

I do think I understand the graphic but I'm not sure how it answers my question. I'm probably either asking a nonsensical question or not expressing it clearly enough. Thanks for taking the time to try to help x = tme figure it out, though.

Ok, I might have assumed that it was easy to read. Sorry. Perhaps this might help:
(//http://i243.photobucket.com/albums/ff277/josephpalazzo/SR-movingaway.jpg) (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html)

a) The graph is drawn with c = 1.
b) Therefore x =t, so a light ray would make a 45[sup:20xeksej]0[/sup:20xeksej] angle with either the t-axis, or x-axis. (Yellow and green lines)
c)The time axis is always flowing so an object at rest would be a vertical line. Two objects at rest, two vertical lines (blue lines).
d)  If you follow just the two blue line and the yellow line, this would be the case of two people at rest sending signals at the speed of light.
e) An object moving would have tilted axis ( red lines).
f) if you follow a blue line( observer at rest), the red line (observer moving) and the green lines (signal), you get the communication between the observer at rest with an observer moving away in this case.
g) Note that the inteception of the light rays with the t-axis. With two observers at rest, the time interval is constant, but between one at rest, the other moving, the time intervals get larger.

Now, in your scenario, there is no length contraction and no time dilation involved simply because you are not measuring the length of an object from one frame to the other, nor are you measuring the time on a clock from one frame to the other. What you are measuring is the velocity of the moving observer, using light signals and each observer is using his own clock in his own frame. So from the graph, if you knew the times at which the signal crosses the t-axis, and the distance between the two objects  (distance between the two parallel blue lines), you would be able to determine v, from x= vt.

Recall that I said you need to know what "events" you want to measure. This determines how you set up your graphic. In this case you are measuring a velocity. And this graph would give you the answer, provided you have a few points on that graph (at least two points with (t[sub:20xeksej]1[/sub:20xeksej],x[sub:20xeksej]1[/sub:20xeksej]), (t[sub:20xeksej]2[/sub:20xeksej],x[sub:20xeksej]2[/sub:20xeksej]))
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 05, 2013, 11:19:49 AM
Quote from: "josephpalazzo"
Quote from: "entropy"
Quote from: "josephpalazzo"The only way I can explain what's happening is on a graphic (sorry if my drawings are not up to par,  :-D )

[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html) ]

The two blue lines would be the case if you and a distant object are at rest with each other, and a signal (in yellow) is sent back and forth. You can see that you would be receiving a signal at equal interval.

The axis in red represents the object moving away from you, and a signal (in green) is sent back and forth. You can see that the time elapsed between each signal is larger and larger.

Who said that a picture is worth a thousand words?  :P

I do think I understand the graphic but I'm not sure how it answers my question. I'm probably either asking a nonsensical question or not expressing it clearly enough. Thanks for taking the time to try to help x = tme figure it out, though.

Ok, I might have assumed that it was easy to read. Sorry. Perhaps this might help:
[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html) ]

a) The graph is drawn with c = 1.
b) Therefore x =t, so a light ray would make a 45[sup:2d0y6rqg]0[/sup:2d0y6rqg] angle with either the t-axis, or x-axis. (Yellow and green lines)
c)The time axis is always flowing so an object at rest would be a vertical line. Two objects at rest, two vertical lines (blue lines).
d)  If you follow just the two blue line and the yellow line, this would be the case of two people at rest sending signals at the speed of light.
e) An object moving would have tilted axis ( red lines).
f) if you follow a blue line( observer at rest), the red line (observer moving) and the green lines (signal), you get the communication between the observer at rest with an observer moving away in this case.
g) Note that the inteception of the light rays with the t-axis. With two observers at rest, the time interval is constant, but between one at rest, the other moving, the time intervals get larger.

Now, in your scenario, there is no length contraction and no time dilation involved simply because you are not measuring the length of an object from one frame to the other, nor are you measuring the time on a clock from one frame to the other. What you are measuring is the velocity of the moving observer, using light signals and each observer is using his own clock in his own frame. So from the graph, if you knew the times at which the signal crosses the t-axis, and the distance between the two objects  (distance between the two parallel blue lines), you would be able to determine v, from x= vt.

Recall that I said you need to know what "events" you want to measure. This determines how you set up your graphic. In this case you are measuring a velocity. And this graph would give you the answer, provided you have a few points on that graph (at least two points with (t[sub:2d0y6rqg]1[/sub:2d0y6rqg],x[sub:2d0y6rqg]1[/sub:2d0y6rqg]), (t[sub:2d0y6rqg]2[/sub:2d0y6rqg],x[sub:2d0y6rqg]2[/sub:2d0y6rqg]))

I did pretty much follow the graph, but now I understand better the point you were making about what is being measured. I think the most fruitful thing for me to ask now based on this last response is to ask about the red, bolded part of your response above about the moving observer. In the hypothetical, how do you determine which observer is the moving observer?
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 05, 2013, 11:40:48 AM
Quote from: "entropy"
Quote from: "josephpalazzo"
Quote from: "entropy"I do think I understand the graphic but I'm not sure how it answers my question. I'm probably either asking a nonsensical question or not expressing it clearly enough. Thanks for taking the time to try to help x = tme figure it out, though.

Ok, I might have assumed that it was easy to read. Sorry. Perhaps this might help:
[ Image (//http://s243.photobucket.com/user/josephpalazzo/media/SR-movingaway.jpg.html) ]

a) The graph is drawn with c = 1.
b) Therefore x =t, so a light ray would make a 45[sup:36otjgkr]0[/sup:36otjgkr] angle with either the t-axis, or x-axis. (Yellow and green lines)
c)The time axis is always flowing so an object at rest would be a vertical line. Two objects at rest, two vertical lines (blue lines).
d)  If you follow just the two blue line and the yellow line, this would be the case of two people at rest sending signals at the speed of light.
e) An object moving would have tilted axis ( red lines).
f) if you follow a blue line( observer at rest), the red line (observer moving) and the green lines (signal), you get the communication between the observer at rest with an observer moving away in this case.
g) Note that the inteception of the light rays with the t-axis. With two observers at rest, the time interval is constant, but between one at rest, the other moving, the time intervals get larger.

Now, in your scenario, there is no length contraction and no time dilation involved simply because you are not measuring the length of an object from one frame to the other, nor are you measuring the time on a clock from one frame to the other. What you are measuring is the velocity of the moving observer, using light signals and each observer is using his own clock in his own frame. So from the graph, if you knew the times at which the signal crosses the t-axis, and the distance between the two objects  (distance between the two parallel blue lines), you would be able to determine v, from x= vt.

Recall that I said you need to know what "events" you want to measure. This determines how you set up your graphic. In this case you are measuring a velocity. And this graph would give you the answer, provided you have a few points on that graph (at least two points with (t[sub:36otjgkr]1[/sub:36otjgkr],x[sub:36otjgkr]1[/sub:36otjgkr]), (t[sub:36otjgkr]2[/sub:36otjgkr],x[sub:36otjgkr]2[/sub:36otjgkr]))

I did pretty much follow the graph, but now I understand better the point you were making about what is being measured. I think the most fruitful thing for me to ask now based on this last response is to ask about the red, bolded part of your response above about the moving observer. In the hypothetical, how do you determine which observer is the moving observer?

In this case, it doesn't matter. The easiest is to take that you are at rest, and your counterpart is moving. Your counterpart can do the same: he can look at his frame at rest, and yours moving. Both of you will agree to the same answer: the velocity between you and him will be v. (Both of you will draw exactly the same graph)

In the case of the twin paradox, here you are measuring two events: departure and arrival. Say the spaceship twin is going to Andromeda. She only needs one clock to measure both events, hence the proper time - this is the time measured by a moving clock. The earth twin needs two clocks: one at departure, and the other at arrival on Andromeda - both clocks are at rest wrt to the earth twin. If you compare the two times you get:

T ' [sub:36otjgkr](proper)[/sub:36otjgkr] = T (1-v[sup:36otjgkr]2[/sup:36otjgkr]/c[sup:36otjgkr]2[/sup:36otjgkr])[sup:36otjgkr]1/2[/sup:36otjgkr]

Moving clocks slow down.

At the same time, she will measure a shortened distance. From her perspective, the distance between earth and andromeda is like a moving stick.

L' [sub:36otjgkr](moving)[/sub:36otjgkr] = L(1-v[sup:36otjgkr]2[/sup:36otjgkr]/c[sup:36otjgkr]2[/sup:36otjgkr])[sup:36otjgkr]1/2[/sup:36otjgkr].

So when she calculates her velocity, V = L'/T ' , she will get the same answer as her twin on earth will have found, V = L/T.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 05, 2013, 02:23:19 PM
Quote from: "josephpalazzo"
Quote from: "entropy"I did pretty much follow the graph, but now I understand better the point you were making about what is being measured. I think the most fruitful thing for me to ask now based on this last response is to ask about the red, bolded part of your response above about the moving observer. In the hypothetical, how do you determine which observer is the moving observer?

In this case, it doesn't matter. The easiest is to take that you are at rest, and your counterpart is moving. Your counterpart can do the same: he can look at his frame at rest, and yours moving. Both of you will agree to the same answer: the velocity between you and him will be v. (Both of you will draw exactly the same graph)

In the case of the twin paradox, here you are measuring two events: departure and arrival. Say the spaceship twin is going to Andromeda. She only needs one clock to measure both events, hence the proper time - this is the time measured by a moving clock. The earth twin needs two clocks: one at departure, and the other at arrival on Andromeda - both clocks are at rest wrt to the earth twin. If you compare the two times you get:

T ' [sub:2k1ykqiw](proper)[/sub:2k1ykqiw] = T (1-v[sup:2k1ykqiw]2[/sup:2k1ykqiw]/c[sup:2k1ykqiw]2[/sup:2k1ykqiw])[sup:2k1ykqiw]1/2[/sup:2k1ykqiw]

Moving clocks slow down.

At the same time, she will measure a shortened distance. From her perspective, the distance between earth and andromeda is like a moving stick.

L' [sub:2k1ykqiw](moving)[/sub:2k1ykqiw] = L(1-v[sup:2k1ykqiw]2[/sup:2k1ykqiw]/c[sup:2k1ykqiw]2[/sup:2k1ykqiw])[sup:2k1ykqiw]1/2[/sup:2k1ykqiw].

So when she calculates her velocity, V = L'/T ' , she will get the same answer as her twin on earth will have found, V = L/T.

Okay, I'm seeing where I misconstrued what "proper time" means (thanks to a surprisingly not particularly good explanation at the Wolfram site). Even with getting that notion squared away, I still see implications that don't square with the notion that there is a contraction that is actual in an absolute sense - which is notion I have been trying to explore. But I don't think there is much value any more in trying to hash it out - at least it doesn't feel that way to me now and there probably hasn't been any value to you in the effort since several posts back. :)
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 05, 2013, 02:44:53 PM
Quote from: "entropy"
Quote from: "josephpalazzo"In this case, it doesn't matter. The easiest is to take that you are at rest, and your counterpart is moving. Your counterpart can do the same: he can look at his frame at rest, and yours moving. Both of you will agree to the same answer: the velocity between you and him will be v. (Both of you will draw exactly the same graph)

In the case of the twin paradox, here you are measuring two events: departure and arrival. Say the spaceship twin is going to Andromeda. She only needs one clock to measure both events, hence the proper time - this is the time measured by a moving clock. The earth twin needs two clocks: one at departure, and the other at arrival on Andromeda - both clocks are at rest wrt to the earth twin. If you compare the two times you get:

T ' [sub:3vavdzff](proper)[/sub:3vavdzff] = T (1-v[sup:3vavdzff]2[/sup:3vavdzff]/c[sup:3vavdzff]2[/sup:3vavdzff])[sup:3vavdzff]1/2[/sup:3vavdzff]

Moving clocks slow down.

At the same time, she will measure a shortened distance. From her perspective, the distance between earth and andromeda is like a moving stick.

L' [sub:3vavdzff](moving)[/sub:3vavdzff] = L(1-v[sup:3vavdzff]2[/sup:3vavdzff]/c[sup:3vavdzff]2[/sup:3vavdzff])[sup:3vavdzff]1/2[/sup:3vavdzff].

So when she calculates her velocity, V = L'/T ' , she will get the same answer as her twin on earth will have found, V = L/T.

Okay, I'm seeing where I misconstrued what "proper time" means (thanks to a surprisingly not particularly good explanation at the Wolfram site). Even with getting that notion squared away, I still see implications that don't square with the notion that there is a contraction that is actual in an absolute sense - which is notion I have been trying to explore. But I don't think there is much value any more in trying to hash it out - at least it doesn't feel that way to me now and there probably hasn't been any value to you in the effort since several posts back. :)

Depends what you mean by "absolute". More importantly, are these effects real? We know that the half-life of cosmic muons is longer than a lab muon's half-life, with the correction exactly as predicted by SR. We know that E = Mc[sup:3vavdzff]2[/sup:3vavdzff]. I have a blog in which I derived that formula exactly how Einstein did it. ( See http://soi.blogspot.ca/2013/06/einstein ... ation.html (http://soi.blogspot.ca/2013/06/einsteins-derivation-of-famous-equation.html)). You see the factor (1 - v[sup:3vavdzff]2[/sup:3vavdzff]/c[sup:3vavdzff]2[/sup:3vavdzff]) [sup:3vavdzff]1/2[/sup:3vavdzff] appearing in the calculation, so it seems that these effects are real.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: entropy on September 05, 2013, 08:42:42 PM
Quote from: "josephpalazzo"
Quote from: "entropy"Okay, I'm seeing where I misconstrued what "proper time" means (thanks to a surprisingly not particularly good explanation at the Wolfram site). Even with getting that notion squared away, I still see implications that don't square with the notion that there is a contraction that is actual in an absolute sense - which is notion I have been trying to explore. But I don't think there is much value any more in trying to hash it out - at least it doesn't feel that way to me now and there probably hasn't been any value to you in the effort since several posts back. :)

Depends what you mean by "absolute". More importantly, are these effects real? We know that the half-life of cosmic muons is longer than a lab muon's half-life, with the correction exactly as predicted by SR. We know that E = Mc[sup:2rdtathu]2[/sup:2rdtathu]. I have a blog in which I derived that formula exactly how Einstein did it. ( See http://soi.blogspot.ca/2013/06/einstein ... ation.html (http://soi.blogspot.ca/2013/06/einsteins-derivation-of-famous-equation.html)). You see the factor (1 - v[sup:2rdtathu]2[/sup:2rdtathu]/c[sup:2rdtathu]2[/sup:2rdtathu]) [sup:2rdtathu]1/2[/sup:2rdtathu] appearing in the calculation, so it seems that these effects are real.

Yes, it does depend on what is meant by "absolute" - and what is meant by "real" and what is meant by "apparent" and "actual". The intuition that I tried to follow to see if it was right is that the fundamental disagreement that occurred earlier in this thread is essentially one of semantics - the meaning intended when people use those words in this context.

I'll use the Doppler experiment analogy (as I did in an earlier post to Solitary) to see if it correctly correlates to the point I'm wondering about with respect to contraction in the direction of movement. In Doppler's experiment (as I'm sure you are aware), if I understand it correctly, the observer standing on the side of the tracks with a train whistle blowing as the train approaches the observer at "high" speed will hear the sound that is produced as a higher pitch than an observer traveling on the train. Is the higher pitch real? Yes it is, but the lower pitch heard by the observer on the train is real, too. Some people might be disturbed by this because they want to think of it in terms of ontological absolutes - if the sound is a higher pitch then it can't also be a lower pitch. A response someone could make is that the sound "appears" to be a higher pitch to the observer outside the train and "appears" to be a lower pitch to observer on the train. What they would intend by that semantic formulation is that both are real but that they are experienced (appear) differently to the two different observers. But someone hearing "appears" used in this context might assume that that isn't the intent; instead that the intent of using "appears" is to express the opposite of "real" - as in an optical illusion can fool you because one line appears longer than another but they are "really" the same length. If that is right, then I wonder if something much like that is the heart of the the disagreement earlier in the thread.

Unless there is something crucial that is intrinsically different about the relativity of what the observers of the train whistle hear compared to the relativity of length in Special Relativity, then I still suspect that this semantic ambiguity is likely to be why the disagreement arose early in this thread. The issue I was trying to track down through most of the discussion with you was whether or not there is something intrinsically different about the relativity of Special Relativity theory and the relativity of the pitch of a sound due to the Doppler effect. I still can't tell about that, so I'm not sure if my initial intuition was right or not.
Title: Re: Why Witch Sabrina Looks Thinner While Riding On Her Broo
Post by: josephpalazzo on September 06, 2013, 10:09:16 AM
Quote from: "entropy"
Quote from: "josephpalazzo"
Quote from: "entropy"Okay, I'm seeing where I misconstrued what "proper time" means (thanks to a surprisingly not particularly good explanation at the Wolfram site). Even with getting that notion squared away, I still see implications that don't square with the notion that there is a contraction that is actual in an absolute sense - which is notion I have been trying to explore. But I don't think there is much value any more in trying to hash it out - at least it doesn't feel that way to me now and there probably hasn't been any value to you in the effort since several posts back. :)

Depends what you mean by "absolute". More importantly, are these effects real? We know that the half-life of cosmic muons is longer than a lab muon's half-life, with the correction exactly as predicted by SR. We know that E = Mc[sup:1y92udvz]2[/sup:1y92udvz]. I have a blog in which I derived that formula exactly how Einstein did it. ( See http://soi.blogspot.ca/2013/06/einstein ... ation.html (http://soi.blogspot.ca/2013/06/einsteins-derivation-of-famous-equation.html)). You see the factor (1 - v[sup:1y92udvz]2[/sup:1y92udvz]/c[sup:1y92udvz]2[/sup:1y92udvz]) [sup:1y92udvz]1/2[/sup:1y92udvz] appearing in the calculation, so it seems that these effects are real.

Yes, it does depend on what is meant by "absolute" - and what is meant by "real" and what is meant by "apparent" and "actual". The intuition that I tried to follow to see if it was right is that the fundamental disagreement that occurred earlier in this thread is essentially one of semantics - the meaning intended when people use those words in this context.

I'll use the Doppler experiment analogy (as I did in an earlier post to Solitary) to see if it correctly correlates to the point I'm wondering about with respect to contraction in the direction of movement. In Doppler's experiment (as I'm sure you are aware), if I understand it correctly, the observer standing on the side of the tracks with a train whistle blowing as the train approaches the observer at "high" speed will hear the sound that is produced as a higher pitch than an observer traveling on the train. Is the higher pitch real? Yes it is, but the lower pitch heard by the observer on the train is real, too. Some people might be disturbed by this because they want to think of it in terms of ontological absolutes - if the sound is a higher pitch then it can't also be a lower pitch. A response someone could make is that the sound "appears" to be a higher pitch to the observer outside the train and "appears" to be a lower pitch to observer on the train. What they would intend by that semantic formulation is that both are real but that they are experienced (appear) differently to the two different observers. But someone hearing "appears" used in this context might assume that that isn't the intent; instead that the intent of using "appears" is to express the opposite of "real" - as in an optical illusion can fool you because one line appears longer than another but they are "really" the same length. If that is right, then I wonder if something much like that is the heart of the the disagreement earlier in the thread.

Unless there is something crucial that is intrinsically different about the relativity of what the observers of the train whistle hear compared to the relativity of length in Special Relativity, then I still suspect that this semantic ambiguity is likely to be why the disagreement arose early in this thread. The issue I was trying to track down through most of the discussion with you was whether or not there is something intrinsically different about the relativity of Special Relativity theory and the relativity of the pitch of a sound due to the Doppler effect. I still can't tell about that, so I'm not sure if my initial intuition was right or not.


The problem in the case of the Doppler effect is better understood if you put detectors instead of human ears. On the detector, you will find higher frequencies when the train is moving towards the detector, and lower when moving away.

Now if you want a philosophical discussion on what is "real", then you need to address this question to a philosopher, not a physicist.  Is what you hear "real"? Is what the detector show "real"? If a dog bites your buttend, is that "real"? :P

Concerning SR and the Doppler effect - even though they seem to be similar, they stem from different principles, and are dealt differently. Similarly, the shift in frequencies when light passes through gravity is also similar but stems from different principles in GR.