Who are the most respected research groups in QG now?

[MTd2]

Although I suspect your post is sarcasm, that would really serve no purpose in a mature discussion forum, and so I am forced to conclude that you are entirely sincere.

You bet. Really powerful in you hypocrisis is. Leech of public money you are!

PS.: Just joking. You probably are some unemployed physicist with too much time in your hands. It is likely that said students are just your fantasy because no good physicist would have your kind of atitude in real life and still be able to keep a place at university. Unless you show that you are someone at a university, I don't believe you, neither in your fantasy university.

 

[Max™]

I'm just curious after seeing these bold statements about String models being the only way to do things.

Is there in fact a useful background independent formulation of String Theory which I've somehow missed in the last... god, decade and a half since I first read up on the subject?If there isn't... doesn't that bother you... just a little?Just noticed the bit about Lorentz violations... I'd say your post is very misleading to say the least. String Theory is a great tool. Reformulating equations and processes in various theoretical frameworks can often provide new insights into them. This is fantastic.

It is not the only way to do things, or the very idea of adS/CFT wouldn't make sense at all, and it is not the holy grail of modern physics just yet. Maybe after the LHC goes live, or the Tevatron beats them to the punch, and they finally prove a prediction of String Theory, you can claim it is the only functioning way to do these things.

http://xkcd.com/171/

The most important thing in science is to be honest, you are not being honest.

 

[Civilized]

Is there in fact a useful background independent formulation of String Theory which I've somehow missed in the last... god, decade and a half since I first read up on the subject? If there isn't... doesn't that bother you... just a little?

I assume by background dependent you mean that String Theory assumes the existence of spacetime as a smooth manifold. This doesn't bother me because I would prefer to have a tractable theory that fits well with the theories we already have as opposed to arbitrarily demanding that the universe should be composed of pre-geometry on the grounds that I know it must be so.

Just noticed the bit about Lorentz violations... I'd say your post is very misleading to say the least.

The LQG that was proposed by Rovelli and Smolin in 1990 was found to be Lorentz violating. Deformed special relativity is obviously Lorentz violating. My understanding is that there are new variants of LQG that are not Lorentz-violating, and that these are also not QFTs (but could be thought of as a generalization of QFT). If you know of a non-string model for quantum gravity that is a Lorentz covariant QFT, I would love to see. I'm still waiting for a peer-reviewed review paper on non-string QG that has been published in the last 12 months.

It [string theory] is not the only way to do things, or the very idea of adS/CFT wouldn't make sense at all, and it is not the holy grail of modern physics just yet.

I understand the logic you are using, if strings in AdS are dual to Conformal fields then why not do away with the strings and just talk about conformal fields. But AdS/CFT is not a quantum theory of gravity, the gravity in AdS is classical Einstein gravity. The comments about strings being the only game in town apply to quantum gravity in particular.

Maybe after the LHC goes live, or the Tevatron beats them to the punch, and they finally prove a prediction of String Theory, you can claim it is the only functioning way to do these things.

No, experimental confirmation can only rule theories out, in can never establish a theory as the only possible truth. To do that you need mathematics, you need impossibility proofs. Now of course impossibility proofs must be handled with care, since as someone pointed out it is always possible to escape the conclusion by failing to satisfy the premises. I am just saying that the current situation is such that failing to satisfy the premises is inconcievable: it means either being Lorentz-violating, being non-renormalizable, or being not a QFT.

You probably are some unemployed physicist with too much time in your hands. It is likely that said students are just your fantasy because no good physicist would have your kind of atitude in real life and still be able to keep a place at university. Unless you show that you are someone at a university, I don't believe you, neither in your fantasy university.

First of all, I'm guessing that English is not your first language. Secondly, you have extrapolated an elaborate ad hominem attack and it happens to be based on falsehoods. I am in fact employed doing research full time at one of the top 5 public schools in the US. My field of expertise is in the theory of quantum computing. Your right that I don't have any students, and that I don't have tenure, but I am far from unemployed --- although I am constantly moving from one short-term appointment to another just like most people who work in physics. The only way I can think of to "prove" this to you without revealing my identity is by showing that I have access to all the paid journal subscriptions that a university like mine typically has, but this would involve violating copyright and is unlikely to satisfy you anyway.

As for whether I have too much time on my hands, that may be so, but writing these posts takes almost no time or effort for me and is an alternative to having a blog to rant on (I prefer to be stimulated to discussion by other people than to stimulating myself to discussion on a blog).

Your right that most professors don't have my attitude, most of them ignore non-string QG altogether and lump it, as I said, into general crackpottery and avoid talking about it.

 

[MTd2]

Your right that most professors don't have my attitude, most of them ignore non-string QG altogether and lump it, as I said, into general crackpottery and avoid talking about it.

you have extrapolated an elaborate ad hominem attack and it happens to be based on falsehoods.

 

[Civilized]

you have extrapolated an elaborate ad hominem attack and it happens to be based on falsehoods.

The only thing I said about a specific person was "You're right", and I meant it sincerely. I also sincerely think that the exchange between you and I in this thread has been an accurate allegory which represents (granted, the extremes of) the exchange between the standard and non-standard physics communities, albeit accurate only in miniature.

I apologize for taking over the non-string QG party in this thread; I've made my point, and I'll leave the thread unless anyone else wants to discuss my assertions with me. I will continue to take issues with other threads where "Quantum Gravity" is discussed entirely in terms of non-standard physics, since this is supposed to be a forum where students come to learn about mainstream peer-reviewed science(btw, no one has responded to my request for a peer-reviewed non-string QG review paper from the last 12 months).

P.S. The criticism of string theory in the XKCD comic above applies to non-string QG to a much, much incomparably greater degree. This is, in fact, the whole problem with non-string QG. If people spent more time elucidating why these models don't contradict relativistic QFT, and elucidating them from the point of view of what us mainstreamers want to hear, answering our doubts before we have them instead of never, than we wouldn't be having this argument today on such ugly terms.

 

[Fra]

I am worried about students receiving misinformation that leads to the end of their studies in physics. At the university, I never mention non-string QG and neither does anyone else, it's only on this forum where non-string QG is vastly over represented as a legitimate field of physics research that I fear that students will become confused. thread is to combat the impression that "Who are the most respected research groups in QG now?" should be entirely about non-string non-standard research.

I've had teachers telling me to face that string theory is THE future of physics, and the of physics or no physics was pretty much string theory or no string theory and that if I am serious I must study string theory or no one will take me seriously. And this guy is a string theory professor. Unfortunately he only convinced about his own inability to see beyond it; which really was not my problem to fix, so he convinced me that I am not meant to do "s"cience, I'm way too stubborn.

I've also come to think that this issue with brainwashing students aren't really much of an issue. Those who are "easily confused" in these matters are perhaps not the best suitable anyway, so they might as well do whatever "they are told to do" as far as I am concerned. After all we're not talking about kids here, it's adults. My only concern today is my tax money.

From the point of view of Science (btw, about Christine and "S" see post#16; "S" vs "s" is wether you think successful science means solving the deep problems, or wether it means "getting hired and stick there")

From the point of view of "S"cience, regarding what is relevant research is clearly up to the individual researcher what he/she chooses to invest part of their life in. If we are talking about "relevance" from the commercial point of view, then we are talking about "s"cience.

/Fredrik

 

[cristo]

This thread has gone way off-topic. Whilst this thread clearly had a bias towards non-string QG to start, there is no excuse for derailing the thread into an argument between string and non-string parties. This helps no-one. Thus, this thread is done.