I printed it out and read all of it I could. It looks like a careful paper, not at all polemical.Tom McCurdy said:Sorry for asking but what are the ramifications of this discovery for string theory.
hi Curious, I can't answer the main thrust of your questionsCurious6 said:Question: this paper should indeed be revolutionary like a member pointed out, but has it actually been seriously accepted by other string theorists and physicists?? Does it really provide definite proof that string theory does not yield gravitons? Why haven't there been any other papers reacting against this one? Just some questions.
Stringy theories are not the only approaches to Quantum Gravity in which one can find gravitons, of course. The emphasis in LQG is on describing gravity through the quantum geometry of space, not by means of gravitons running around on a fixed rigid space. But one CAN construct gravitons in LQG.marcus said:...
I dont think there is any question about the string approach being able to crank out gravitons. Padma doesnt challenge this.
what padma's paper brings into question is whether yielding gravitons is the same as yielding gravity----the gravity we know and love from Gen Rel.
It could be that gravitons dont really exist in nature and that they are just a (not completely satisfactory) man-made mathematical approximation.
It could be that gravitons are a mathematical tool which sometimes, in some situations, is appropriate to use in describing how the gravitational field works.
what I have said here is only the beginning---something we should recognize at the outset. Padma goes much farther than this and indicates that gravitons (a la string) actually give a faulty answer about gravity.
Just to have the link handy
From Gravitons to Gravity: Myths and Reality
(as you can see it was just September it came out, not time yet for string folk to respond. I hope they do, as I expect you too)
I'm sorry marcus, but as everyone here knows, you've stated quite plainly numerous times that you don't believe in the idea of gravitons. Of course you said this because you thought that lqg - your religion - is inconsistent with the idea of the graviton so that this idea must be unholy.marcus said:Stringy theories are not the only approaches to Quantum Gravity in which one can find gravitons, of course. The emphasis in LQG is on describing gravity through the quantum geometry of space, not by means of gravitons running around on a fixed rigid space. But one CAN construct gravitons in LQG.
Marcus is in pretty good company. There are some fairly well regarded researchers who share that opinion.jeff said:I'm sorry marcus, but as everyone here knows, you've stated quite plainly numerous times that you don't believe in the idea of gravitons.
I assume that assertion is a private joke.jeff said:Of course you said this because you thought that lqg - your religion - is inconsistent with the idea of the graviton so that this idea must be unholy.
Different interpretations of that statement by Rovelli are possible.jeff said:You've changed your tune now because yesterday I pointed out that carlo rovelli states in the introductory chapter of his new book that...
"What we need is not just a technique for computing, say, graviton-graviton scattering amplitudes (although we certainly want to be able to do so, eventually)"
Of course I've tried to explain this to you many times.
Name two.Chronos said:Marcus is in pretty good company. There are some fairly well regarded researchers who share that opinion.
Name a plausible one.Chronos said:Different interpretations of that statement by Rovelli are possible.
You've got a lot of nerve to reprimand me for going off topic, especially since you do so all the time. In fact my remarks where well within the range of what is on topic in this post, namely gravitons.marcus said:Jeff this is thread is not about my personality and whatever opinions you say I have expressed in the past, nor about your personality and related issues, or about Carlo Rovelli and the new book by him which apparently concerns you. Please start another thread if you feel there are not enough about those topics.
Let's focus this thread on T. Padmanabhan around the article of his that selfAdjoint started the thread by citing, namely:
From Gravitons to Gravity: Myths and Reality
My experience has been that some forms of participation always end up diverting a thread from the main topic and redirecting it into discussing personality issues. Overall the best way to handle this may be is not to fight it (because fighting it just leads to more vituperation) but just ignore it, and maybe start a separate thread for talking persons and their animosities and what this one said and that one said.
This would be an incorrect assumption. Padmanabhan is coming from the direction of the most credible part of the alternative cosmology community, and thus has an interest is showing that mainstream GR-SM Cosmology is flawed. He needs to defeat this paradigmn to establish himself as an important scientific figure, and to the extent that string theory would bolster conventional GR cosmology, this is a problem for him.Thanu Padmanabhan has never written any LQG papers---not a supporter of some rival to string--- may be assumed disinterested, or so I reckon.