Atheistforums.com

Science Section => Science General Discussion => Physics & Cosmology => Topic started by: Solitary on May 19, 2014, 11:26:08 AM

Title: String Theory
Post by: Solitary on May 19, 2014, 11:26:08 AM
What a remarkable intellect and memory: http://youtu.be/YtdE662eY_M   :borg: Solitary
Title: Re: String Theory
Post by: SGOS on May 19, 2014, 12:14:49 PM
I actually think I may have understood that.
Title: Re: String Theory
Post by: josephpalazzo on May 19, 2014, 02:37:47 PM
I thought there was something new in this field, until Greene started to talked about the LHC which wasn't yet in operation. That video was posted on youtube in 2008. That's fucking old news. Six years after, the LHC hasn't confirmed ST, and isn't likely to do so in the near future. Here's a more sober and updated view (from 2013):

QuoteThe probability (in my Bayesian estimation) that the LHC will discover BSM physics has gone from fairly likely (as witnessed by my previous willingness to take even-odds) to rather unlikely. N.B.: that’s not quite the same thing as saying that there’s no BSM physics at these energies; rather that, if it’s there, the LHC won’t be able to see it (at least, not without accumulating many years worth of data).

http://www.math.columbia.edu/~woit/wordpress/?p=6069
Title: Re: String Theory
Post by: stromboli on May 19, 2014, 03:41:59 PM
Quote from: josephpalazzo on May 19, 2014, 02:37:47 PM
I thought there was something new in this field, until Greene started to talked about the LHC which wasn't yet in operation. That video was posted on youtube in 2008. That's fucking old news. Six years after, the LHC hasn't confirmed ST, and isn't likely to do so in the near future. Here's a more sober and updated view (from 2013):


Right. I was waiting for somebody more qualified than me to point that out.

http://www.youtube.com/watch?v=TGRdeJkdagA
Title: Re: String Theory
Post by: AllPurposeAtheist on May 19, 2014, 03:45:49 PM
I have a theory about string too. It keeps my shoes from falling off. Sometimes it breaks and then getting the ends back in the little holes is hard. :think:
It's a conspiracy. :eek:
Title: Re: String Theory
Post by: AllPurposeAtheist on May 21, 2014, 02:39:32 AM
Quote from: Solitary on May 20, 2014, 01:46:02 PM
What happens when all this searching finds out how God's mind works---and there is nothing there?  :eek: :eek: Solitary
Pretty much what we have right now,  a bunch of delusional people in denial.
Title: Re: String Theory
Post by: Shol'va on May 21, 2014, 02:27:46 PM
String Theory is just another theory by scientists to string us along into buying into the unsupported assertion that realism and materialism are true.
Right?
Title: Re: String Theory
Post by: josephpalazzo on May 21, 2014, 04:49:25 PM
Don't say it too loud, Casparov might hear you, and then we'll never hear the end of it.
Title: Re: String Theory
Post by: josephpalazzo on May 22, 2014, 11:27:09 AM
It's okay, Casparov has admitted defeat.

See: http://atheistforums.com/index.php?topic=4770.msg1017170#msg1017170
Title: Re: String Theory
Post by: stromboli on May 22, 2014, 11:42:38 AM
Quote from: josephpalazzo on May 22, 2014, 11:27:09 AM
It's okay, Casparov has admitted defeat.

See: http://atheistforums.com/index.php?topic=4770.msg1017170#msg1017170

Lol, rubbing it in JP?

:axe:
Title: Re: String Theory
Post by: josephpalazzo on May 22, 2014, 12:06:52 PM
It's a slow day... well, not exactly. I'm working on my next blog - Effective Field Theory - heavy stuff, and I need some break time... and Casparov is perfect a scapegoat to poke fun at... I'm sadistic by nature...
Title: Re: String Theory
Post by: Solitary on May 22, 2014, 12:29:16 PM
I know, I found out when I first met you on the forum. :winkle: :smile: SmOff :fU: He! He! Solitary
Title: Re: String Theory
Post by: josephpalazzo on May 22, 2014, 04:52:45 PM
 I was very gentile with you... :biggrin2:
Title: Re: String Theory
Post by: stromboli on May 22, 2014, 09:47:52 PM
Quote from: josephpalazzo on May 22, 2014, 12:06:52 PM
It's a slow day... well, not exactly. I'm working on my next blog - Effective Field Theory - heavy stuff, and I need some break time... and Casparov is perfect a scapegoat to poke fun at... I'm sadistic by nature...

Lol. Don't worry. I've never confused you with Mary Poppins.
Title: Re: String Theory
Post by: Unbeliever on July 23, 2014, 07:07:14 PM
I wonder whether the dualities of string theories have any connection to the geometric dualities of the Platonic solids? Or this merely coincidental?
Title: Re: String Theory
Post by: josephpalazzo on July 24, 2014, 09:21:39 AM
Quote from: Unbeliever on July 23, 2014, 07:07:14 PM
I wonder whether the dualities of string theories have any connection to the geometric dualities of the Platonic solids? Or this merely coincidental?

There are lots of dualities: the wave/particle duality; in the Hilbert space, there is a duality between the bra  and the ket vectors, and so on. The word "duality" simply means "two". Wherever there are two kinds of things that are somewhat related, there is a duality. In String Theory, the dualities are related to some transformations: in one case, called T-duality, the two string theories are related by the transformation of the distances: R â†' 1/R. The types IIa with IIB, and Heterotic E8xE8 with Heterotic SO(32) are T-duals. While the S-duality is related by the couplig transformation, gâ†' 1/g. The types I with Heterotic SO(32), and  type IIB with itself are S-duals.
Title: Re: String Theory
Post by: Solitary on July 24, 2014, 11:22:36 AM
Light and dark, up and down, in and out, big and small, mind and body, human and animal, smart and dumb, reality and fantasy, gravity and energy, etc. So what?  :think: :pidu: Solitary
Title: Re: String Theory
Post by: Unbeliever on July 30, 2014, 06:33:27 PM
Quote from: josephpalazzo on July 24, 2014, 09:21:39 AM
There are lots of dualities: the wave/particle duality; in the Hilbert space, there is a duality between the bra  and the ket vectors, and so on. The word "duality" simply means "two". Wherever there are two kinds of things that are somewhat related, there is a duality. In String Theory, the dualities are related to some transformations: in one case, called T-duality, the two string theories are related by the transformation of the distances: R â†' 1/R. The types IIa with IIB, and Heterotic E8xE8 with Heterotic SO(32) are T-duals. While the S-duality is related by the couplig transformation, gâ†' 1/g. The types I with Heterotic SO(32), and  type IIB with itself are S-duals.

Well, yes, I understand that part, but I noticed a possibly interesting link, specifically between the Platonic solids and the dualities of the coupling constants in string theory.

I was reading a book about symmetry (appropriately titled "Symmetry") by Marcus du Sautoy, in which he discusses these Platonic dualities (pg. 57-58). The cube is dual to the octahedron, the dodecahedron is dual to the icosahedron, and the tetrahedron is dual to itself. This reminded me of reading about the coupling strength dualities of the various string theories in Brian Greene's book "The Elegant Universe" (pg. 313) in which he says that the coupling strength of Type-I is dual to the coupling strength of Heterotic-SO(32), the coupling strength of Heterotic-E8xE8 is dual to the coupling strength of type-IIA, with type IIB being dual to itself.

It just seemed to me to be of a similar pattern, and I thought there could be some subtle connection. But I'm neither scientist nor mathematician enough to be able to tell if there is any significance to this.
Title: Re: String Theory
Post by: Solitary on July 31, 2014, 12:42:46 AM
Quote from: josephpalazzo on May 22, 2014, 04:52:45 PM
I was very gentile with you... :biggrin2:
And wrong! Ha! Ha! Solitary
Title: Re: String Theory
Post by: josephpalazzo on July 31, 2014, 08:28:38 AM
Quote from: Unbeliever on July 30, 2014, 06:33:27 PM
Well, yes, I understand that part, but I noticed a possibly interesting link, specifically between the Platonic solids and the dualities of the coupling constants in string theory.

I was reading a book about symmetry (appropriately titled "Symmetry") by Marcus du Sautoy, in which he discusses these Platonic dualities (pg. 57-58). The cube is dual to the octahedron, the dodecahedron is dual to the icosahedron, and the tetrahedron is dual to itself. This reminded me of reading about the coupling strength dualities of the various string theories in Brian Greene's book "The Elegant Universe" (pg. 313) in which he says that the coupling strength of Type-I is dual to the coupling strength of Heterotic-SO(32), the coupling strength of Heterotic-E8xE8 is dual to the coupling strength of type-IIA, with type IIB being dual to itself.

It just seemed to me to be of a similar pattern, and I thought there could be some subtle connection. But I'm neither scientist nor mathematician enough to be able to tell if there is any significance to this.

I guess it all depends on the nature of the duality. For instance, if you take an equation in type IIA that contains R, the radial distance, and substitute 1/R, you get the equivalent equation in type IIB. Does that mean anything? Witten proposed that it was symptomatic of a theory in higher dimension - String Theory in 10-D to a hypothetical M-Theory in 11-D - but no one has figured out that M-Theory so far. Note that these dualities in ST are mathematical in nature. We don't really know if it corresponds to anything physical, and if it does, what is that physical reality. We know that the particle/wave duality is physical, and we were able to transform that into a mathematical language, which we call Quantum Mechanics. In ST, we have the reverse, a mathematical duality, but we are still uncleared as to what physical reality that would correspond to.

EDIT: See https://en.wikipedia.org/wiki/M-theory

Title: Re: String Theory
Post by: Unbeliever on July 31, 2014, 06:41:41 PM
OK, thanks Joe!
Title: Re: String Theory
Post by: Desdinova on August 04, 2014, 12:51:06 PM
(http://oddstuffmagazine.com/wp-content/uploads/2012/11/u8BFJ.gif)
Title: Re: String Theory
Post by: josephpalazzo on August 05, 2014, 02:44:53 PM
Quote from: Solitary on August 04, 2014, 12:24:50 PM
QuoteWe know that the particle/wave duality is physical


SmOn Who is this we?

when physicist talk about the wavelength of a photon, they are not referring to a property of an individual photon but to a characteristic of the mathematical function that that describes a statistical ensemble of identical photons. The same can be done with electrons or any other particle. The electron, photon, and all other submicroscopic objects are localized particles and their wavelike effects refer to their only to the statistical behavior of a large group of them.

It does not matter whether you are trying to measure  a particle property or a wave property. YOU ALWAYS MEASURE PARTICLES. Quantum mechanics is just a statistical theory like statistical mechanics, reducible to particle behavior. Keep the cards and letters coming.  Solitary


Not really. A single electron can exhibit wave properties. And yet no one thinks that the single electron is made up of a statistical ensemble of identical particles.
Title: Re: String Theory
Post by: josephpalazzo on August 07, 2014, 06:30:56 AM
Quote from: Solitary on August 07, 2014, 12:39:29 AM

First of all, you cannot observe the "wave like distribution," or interference, with only one electron. The interference pattern emerges statistically, after many electrons have been detected at the screen.

Yes it happens with a single photon. Google: Machâ€"Zehnder interferometer.

QuoteThe electron must be moving to acquire mo and a wave property. We are thus dealing with a momentum-wave duality rather than a particle-wave duality. When an electron is not accelerated, it could be bound as a particle with mass but it has no mo and no wave properties.

Speculation.

QuoteIf the energy given to the particle stays with the particle then that means there is such a thing as absolute rest. With absolute rest Newton is in and Einstein is but a pretender he always was. :razz: Solitary


You're out of luck. GR has been verified over and over again over the last 99 years. (Hint: next year will mark GR's 100 years,  :biggrin2:)
Title: Re: String Theory
Post by: josephpalazzo on August 07, 2014, 02:24:54 PM
Quote from: Solitary on August 07, 2014, 01:58:43 PM
You are correct a single electron does have wave properties, but only when it is moving, which is my point. Solitary

The Heisenberg Uncertainty Principle forbids any particle to be at rest. Without this principle, quantum fluctuations can't exist... oh wait, QM can't exist.