Why Witch Sabrina Looks Thinner While Riding On Her Broom.

Started by Solitary, June 11, 2013, 02:02:30 AM

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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
There is nothing more frightful than ignorance in action.

Solitary

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
There is nothing more frightful than ignorance in action.

Jason78

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.
Winner of WitchSabrinas Best Advice Award 2012


We can easily forgive a child who is afraid of the dark; the real
tragedy of life is when men are afraid of the light. -Plato

josephpalazzo

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.

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.  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
There is nothing more frightful than ignorance in action.

josephpalazzo

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.

Solitary

There is nothing more frightful than ignorance in action.

josephpalazzo

I'm beginning to believe that your reading skills are very limited. Sorry If I called you a wacko, you're really a retard.   :(

Colanth

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.
Afflicting the comfortable for 70 years.
Science builds skyscrapers, faith flies planes into them.

Solitary

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
There is nothing more frightful than ignorance in action.

Colanth

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.
Afflicting the comfortable for 70 years.
Science builds skyscrapers, faith flies planes into them.

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. It's really not that hard, as you say, even dummies can do it. :roll:  Solitary
There is nothing more frightful than ignorance in action.

josephpalazzo

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.

Colanth

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.
Afflicting the comfortable for 70 years.
Science builds skyscrapers, faith flies planes into them.

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? 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
There is nothing more frightful than ignorance in action.