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View Full Version : Does John H. Schwarz now believe in Verlinde`s gravity?


MTd2
Nov18-10, 07:23 PM
http://arxiv.org/abs/1011.4106

Gravity as an Entropic Phenomenon

Abhiram Chivukula, John H. Schwarz
(Submitted on 17 Nov 2010)
The unification of gravity with the three other forces has been an important goal of physics for some time now, because a quantum theory of gravity is necessary to explain the universe at its earliest moments. Its pursuit has largely assumed gravity's independent existence, but E. Verlinde proposed that gravity is not a fundamental force but a macroscopic phenomenon that emerges as a result of thermodynamic principles applied to the information of mass distributions. Under this framework we consider the roles played by quantum microstates, entanglement, information theory, the AdS/CFT Correspondence, and String Theory in general. We also ask whether Verlinde's proposal suggests that action principles should be thermodynamic in nature.

negru
Nov18-10, 08:05 PM
That looks like a highschool summer collaboration, so no I don't think so.

MTd2
Nov18-10, 08:20 PM
That guy is in an undergrad:

http://blacker.caltech.edu/hovselist/detailed.php?member=1219

But does it matter? Why would JH support something that he disagrees?

negru
Nov18-10, 08:37 PM
Wow, and a senior nonetheless. Lots of profs at my school do projects on things varying from hidden variable qm to very weird stuff, even though they obviously don't believe in them. Nothing to get worried about.

And anyway, the paper looks like addressing what entropic gravity would imply for string theory and vice-versa, a rather sensible thing to do if you're checking the consistency of a theory.

negru
Nov18-10, 08:43 PM
You might as well be asking how can Schwarz's standards have fallen so much that his references include blogs and wikipedia.

atyy
Nov18-10, 10:18 PM
http://arxiv.org/abs/1006.1902
Wilsonian Approach to Fluid/Gravity Duality
Irene Bredberg, Cynthia Keeler, Vyacheslav Lysov, Andrew Strominger
"In this section we want to show that the first law of thermodynamics together with isentropy of the radial flows is equivalent to a radial component of the Einstein equation ... A general type of equivalence between the Einstein equation and the first law has been demonstrated by Jacobson [43], see also [50]. We suspect our equivalence is related to this - as well as the recent work [44] - but we defer this issue to future consideration."

String theory crackpots are much more wonderful than the garden variety type!

marcus
Nov18-10, 11:08 PM
http://arxiv.org/abs/1006.1902
Wilsonian Approach to Fluid/Gravity Duality
Irene Bredberg, Cynthia Keeler, Vyacheslav Lysov, Andrew Strominger
"In this section we want to show that the first law of thermodynamics together with isentropy of the radial flows is equivalent to a radial component of the Einstein equation ... A general type of equivalence between the Einstein equation and the first law has been demonstrated by Jacobson [43], see also [50]. We suspect our equivalence is related to this - as well as the recent work [44] - but we defer this issue to future consideration."

String theory crackpots are much more wonderful than the garden variety type!

Nobody really wants to suggest that Andy Strominger, Cynthia Keeler, John H. Schwarz are crackpots, even in jest.
I'll try to introduce a note of sobriety amidst all the merriment.

MTd2's headline was misleading, I think. Schwarz certainly seems to take Verlinde seriously but he does not indicate that he believes the Entropic Gravity hypothesis. There's a lot of Schwarz in this paper IMHO. And in science you clearly don't have to believe in something in order to explore its ramifications.

Chivukula Schwarz is a real collaboration. There is a serious and at places rather deep working out of the consequences of Verlinde's idea. They also lay out suggestions for further investigation with Entropic Gravity as a starting point.

atyy
Nov19-10, 12:07 AM
Hey - there's nothing wrong with being a crackpot - as long as you are a good crackpot!

Demystifier
Nov19-10, 04:00 AM
Hey - there's nothing wrong with being a crackpot - as long as you are a good crackpot!
Any example?

Demystifier
Nov19-10, 04:02 AM
And in science you clearly don't have to believe in something in order to explore its ramifications.

That's true. In fact, an ideal scientist should not be guided by his believes at all.

atyy
Nov19-10, 07:02 AM
Any example?

I was thinking of Schwarz and Strominger.

But how about Bekenstein?

Demystifier
Nov19-10, 07:18 AM
I was thinking of Schwarz and Strominger.

But how about Bekenstein?
They are all good, but why do you refer to them as crackpots?

atyy
Nov19-10, 08:02 AM
They are all good, but why do you refer to them as crackpots?

Well, before you are proven right you are a crackpot, after you are proven right you are a prophet.

MTd2
Nov19-10, 08:39 AM
atyy, I see what you mean. You refer to people such as Hannes Alven:

http://en.wikipedia.org/wiki/Hannes_Alfv%C3%A9n

marcus
Nov19-10, 11:28 AM
atyy, I see what you mean. You refer to people such as Hannes Alven:

http://en.wikipedia.org/wiki/Hannes_Alfv%C3%A9n

The correct term for Hannes Alfven is maverick, not crackpot.

He was a bit eccentric, had some wrong ideas and some right ideas, got the 1970 Nobel prize in physics for magneto-hydrodynamics (behavior of plasmas in magnetic fields etc...)

He was trained as an Electrical Engineer, he could publish his physics papers in peer-review journals but not always in the best ones. The top journals often turned him down. He was tenured faculty at San Diego.

Crackpot is an important word symbolizing the OSTRACISM reflex by which the scientific community maintains itself. The traditional science ethic requires careful consideration and critical review of fellow scientists' ideas. Patient attention is accorded, and counter-argument provided.
But there isn't time to give that to people who are too far gone. So we have a special category of people you aren't morally obliged to argue with. These are the crackpots, who don't even make it in the door. You don't have to listen to them.
The mechanism of rejecting people too far gone to be covered by the normal courtesy of science is really important. It is a judgement call, collectively arrived at, and essential to the functioning of the community.

I don't think it is safe to play games with the meaning of an important word like that. The term should be kept sharply defined. It should not be applied to scientists whose ideas are merely offbeat or unfashionable---call them mavericks or think of some other word.

=====================

Erik Verlinde is certainly no crackpot! Neither is Lee Smolin. The community actually benefits from outriders who don't stay with the wagon-train---people who stubbornly go their own way, who jump the rut, head off in a different direction, but still remain scientists.

They may often, or even always, be wrong! They shake the others up, cause ideas to be questioned and often rethought.

The ethic says to have a high tolerance for different opinion---up to a certain point---and that makes sense because even though uncomfortable the presence of non-conforming opinion contributes to the process.

These people can have character flaws too. (not Verlinde or Smolin necessarily but some can). Don't waste your time denigrating them, whining and moaning about them, excoriating them, demonizing them etc. It is just boring. Mavericks are part of science so get over it.
That's just my advice. This is really directed at what was going on in that other thread---badmouthing Garrett Lisi, the editors of the Scientific American, and anything else that came to mind. :biggrin:

marcus
Nov19-10, 12:02 PM
BTW MTd2, thanks for pointing out this paper. It has a lot of John Schwarz in it! Deep interesting thinking in response to the Verlinde business. I am not saying that I agree or side with Schwarz or that Schwarz agrees with Verlinde. The game is not about choosing sides. It's interesting. He brings out stuff I wouldn't have thought of, and raises issues I don't completely understand, and will have to learn about.

Demystifier made some extremely good points in this thread too. It's not a scientist's job to believe but to follow the ideas and see where they go.

MTd2
Nov19-10, 12:07 PM
Anyway, both Verlinde and Schwarz are using Holography as a way to find a non perturbative and definitive formulation of string theory in terms of matrices. This is what should be expected from Verlinde, given that he gave one the first formulations.

marcus
Nov19-10, 03:07 PM
And in science you clearly don't have to believe in something in order to explore its ramifications...

That's true. In fact, an ideal scientist should not be guided by his beliefs at all.

Hadn't thought of that, but I think you could be right!

Demystifier
Nov22-10, 03:25 AM
I know many physicists who are also very religious. I couldn't be able to see any reflections of their religious beliefs on their scientific research.

xepma
Nov22-10, 04:22 AM
As of today, John H. Schwarz no longer appears as an author of the paper.

Demystifier
Nov22-10, 04:31 AM
As of today, John H. Schwarz no longer appears as an author of the paper.
That's very very interesting ...

Fra
Nov22-10, 04:32 AM
As I see it the problem isn't beliefs in itself. Everyone has beliefs and it does govern our behaviour, and rationally so. Beliefs are closely related to the more technical term expectation. And to quantify degrees of beliefs is all about what the origin of probability theory.

I think the history of science was to seek some kind of RATIONAL belief, that could be justified in terms of "objective evidence", as opposed to the IRRATIONAL beliefs that was based on things that couldn't be quantified in terms of objective evidence, like "whatever the pope or preasts say" or whatever you read in some book.

I think the action every system and researchers is strongly related to it's beliefs. For example, the reason why mankind invested alot of money in LHC is based on beliefs & expectations that it's likely to increase our knowledge.

I think rationality is judged relative to the environment. If your action is based on objective evidence, then the belief will appear justified and rational (that doesn't mean however that it's "true" in some eternal sense)

So while I understand what Demystifier means, and he has a point, I still wanted to make this note.

We all have expectations, and they do influence our actions, and this is initself rational.

IMHO, what science should try to distinguish and define is rational beliefs from irrational beliefs, not deny the importance of expectations influencing actions per see.

/Fredrik

MTd2
Nov22-10, 04:35 AM
The paper was not changed though, it seems. In the first version he also appeared not as an author, but as a mentor. The change only happened in the arxiv.org page.

marcus
Nov22-10, 10:02 AM
That's very very interesting ...

Does seem significant.

From the start, in the first version posted, Schwarz was NOT listed as author in the paper. Abhiram was the sole author and he THANKED SCHWARZ in the acknowledgements at the end. An author does not thank himself in the acknowledgements.

Also on the title page Abhiram appears as solo author with "Mentor: John H. Schwarz" in italics underneath.
In italics on a separate line makes it clear that this is information about Avisham (that his mentor was JHS) analogous to the information in the next line---that Abhiram's institution affilation is California Institute of Technology.

The simplest explanation is it's clear from the paper that Schwarz never declared authorship. He admitted to mentorship and allowed himself to be thanked in the last section.
Therefore there was a temporary clerical error in the way the paper was catalogued at arxiv, which has now been corrected.

As MTd2 points out, no change has occurred in in the paper itself----only in how arxiv lists it.

My guess is that the error was caused by Abhiram when he uploaded it to arxiv. He filled out some form wrong, put the wrong information in some box. But it could have been an error on the part of some Arxiv clerical worker, or something else.

So I don't suspect Schwarz of flirting or being coy---no intentional "yes I did--no I didn't" peek-a-boo funny business.

Although there is a remote possibility that the mis-cataloguing was an intentional fake-blunder to call intention to the paper when it first appeared.
====================

I still think the paper has a lot of Schwarz in it. There are reflections of a depth that I would not expect even of a PhD student---certainly not of a Caltech undergrad.

MTd2
Nov22-10, 10:18 AM
So, a classical string theorist is still with boring ideas....

marcus
Nov22-10, 10:56 AM
He still has ideas---I wouldn't call them boring.

MTd2
Nov22-10, 11:03 AM
I am not questioning if he has ideas, whether good or bad. I was a bit enthusiastic that one more important string theorist would leave behind what I consider boring, repetitive, dull, excessively complex, full of dead end. etc, ideas. Now I am bored.

atyy
Nov22-10, 11:17 AM
I still think the paper has a lot of Schwarz in it. There are reflections of a depth that I would not expect even of a PhD student---certainly not of a Caltech undergrad.

Have you never heard: flunk out of Caltech, get As at MIT?

MTd2
Nov22-10, 11:17 AM
Oh, I just read your post #24. You added a lot of stuff. Hmm. Maybe that Indian guy is genius.

negru
Nov22-10, 11:19 AM
That sure got the paper some attention. Now I'll know when I submit my papers, I'll put Einstein as co-author. Genius, why didn't I think of it before?

marcus
Nov22-10, 12:07 PM
... I was a bit enthusiastic that one more important string theorist would leave behind what I consider boring, repetitive, dull, excessively complex, full of dead end. etc, ideas. ...

When people people shift their research interest they don't always make a political declaration about it. They don't necessarily shift permanently or 100%. Or run a different flag up the mast. It can be subtle.

Demystifier
Nov23-10, 03:39 AM
That sure got the paper some attention. Now I'll know when I submit my papers, I'll put Einstein as co-author. Genius, why didn't I think of it before?
I'll put Witten. Then it will be interesting to see who will attract more attention. :wink:

P.S. Is there a volunteer who would put Hawking? Just for the sake of experiment. :biggrin:

Demystifier
Nov23-10, 03:47 AM
My guess is that the error was caused by Abhiram when he uploaded it to arxiv. He filled out some form wrong, put the wrong information in some box.

As it was the first paper written and submitted by Abhiram, the most likely possibility is that he thought that he was obliged to put Schwarz into the list of authors. Next time he will know.

arivero
Nov23-10, 06:13 AM
That sure got the paper some attention. Now I'll know when I submit my papers, I'll put Einstein as co-author. Genius, why didn't I think of it before?

http://en.wikipedia.org/wiki/Alpher%E2%80%93Bethe%E2%80%93Gamow_paper

qsa
Nov23-10, 02:26 PM
He still has ideas---I wouldn't call them boring.

I am not sure what the fuss is all about. Since the paper seems to examine verlinde's theory in a very critical manner, also the author seems to try to prove the correctness of string theory in case verlinde's idea pan out (without contradicting string).

This is what I understood since I read the paper more carefully because it sort of answered my question in my "gravity in bound state" thread.

http://www.physicsforums.com/showthread.php?t=432711 post #13

"Thank you for your response. the classical calculation is well known to me, but I guess I am not clear in my question. Since I am trying to get some connection between wavefunction(QM) and gravity I am more asking about the nature of QG. So when two waves overlap that is equivalent (or is it) to two particles sitting on top of each other, then shouldn't the particles gravities affect each other since their potential is of 1/r and r is going to zero (or maybe G going to 1). Or I guess the whole wavefunction must be taken into account. In this case you should see some effect if both are delta function sitting near each other. but the wave function must carry G somewhere (probably involving all constants but changing with distance). Any other ideas!"


see thumbnail (page 14 of the paper)


http://arxiv.org/PS_cache/arxiv/pdf/1011/1011.4106v2.pdf