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A Jewel at the Heart of Quantum Physics

simonsfoundation.org

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Re: A Jewel at the Heart of Quantum Physics

#41

Post by Tycho »

ISL wrote: post #9
gruseom wrote: post #2

Is anyone here familiar with this work? I would like to hear more about it. At a minimum, this article is very much better than the usual science blog filler—it contains signs of a genuine conceptual breakthrough. For example: “You can easily do, on paper, computations that were infeasible even with a computer before.” That doesn't happen very often! Or this: [T]he new geometric approach to particle interactions remo…

Physicist here: This has a higher probability of being important than your usual science blog material. The Simons Foundation is a serious entity, backed with serious funds. Arkani-Hamed had some compelling things to say recently at a talk and colloquium at our university; looking forward to learning more.

backed with serious funds

As I suspected, The Simons Foundation is backed by Jim Harris Simons, mathemetician and the most successful hedge fund manager of all time (Google Medallion Fund and Renaissance Technologies for more info). Cool.

Re: A Jewel at the Heart of Quantum Physics

#42

Post by biot »

selimthegrim wrote: post #17
freyrs3 wrote: post #4

The paper from the arxiv mentioned in the article: http://arxiv.org/pdf/1212.5605v1.pdf

I was talking to a friend in the physics department at Stanford a few months ago about how one of the people whose work is cited in this paper (Greg Moore of Rutgers) had found analytic expressions purely rooted in geometry for Bethe Ansatz[1] results in (1+1) dimensional systems. Based on that, I told my friend I believed these "physical mathematics types" (as they call themselves) were on to something. He concurred…

In other words, you made a comment four months ago that simple, geometric models are likely to be important?

Re: A Jewel at the Heart of Quantum Physics

#43

Post by TeMPOraL »

ssivark wrote: post #23
tlb wrote: post #20

Rejecting unitarity is a bold thing to do. What can it mean for the probabilities of alternatives to sum to more than 1?

No, they do not reject unitarity. The theory is still unitary. However, unitarity is not built-in to the theory... the theory talks about some other ideas and structures, and it turns out that all the answers you compute respect unitarity -- like it should!

I understand it's kind of like "let's start without unitarity and locality baked in explicitly in the model and see where it leads and if they come out implicitly in the results".

Re: A Jewel at the Heart of Quantum Physics

#44

Post by rational_me »

has2k1 wrote: post #33
noonespecial wrote: post #5

Every once in a while I get the feeling that the greatest discoveries are still ahead and these next few decades might be the real "golden age of science". The "individual genius" phase is just behind us and the "collaborative brilliance" phase is just beginning.

It is possible that Gravity as we know it is an illusion. For example, the Newtonian take on Gravity was that it was a force. That according to Einstein was illusory, Gravity was really a geometric manifestation due to the curvature of space-time. With that take Gravity as we know it is different from the Gravity as was once known. However the Newtonian view that Gravity is a force can and still does facilitate usefu…

>I took QFT some years back and it also went over my head. There is still that mental gap of where the only way you can think about time is via time-(in)dependent wave function.

Total bullshit. The wave function is time dependent.

Re: A Jewel at the Heart of Quantum Physics

#45

Post by ttctciyf »

freyrs3 wrote: post #4

The paper from the arxiv mentioned in the article: http://arxiv.org/pdf/1212.5605v1.pdf

(non physicist, non mathematician) The current excitement seems to be to do with a forthcoming paper from Arkani Hamed and his student Jaroslav Trnka. The pdf at http://www.staff.science.uu.nl/~tonge105/igst13/Trnka.pdf has some details of that, I think.

Edit to add:

The pdf is slides from a talk by Trnka. Video of a later talk on the same topic by Arkani Hamed is at http://susy2013.ictp.it/video/05_Friday/2013_08_30_Arkani-Ha... - he sounds very excited!

Re: A Jewel at the Heart of Quantum Physics

#46

Post by Steuard »

gruseom wrote: post #2

Is anyone here familiar with this work? I would like to hear more about it. At a minimum, this article is very much better than the usual science blog filler—it contains signs of a genuine conceptual breakthrough. For example: “You can easily do, on paper, computations that were infeasible even with a computer before.” That doesn't happen very often! Or this: [T]he new geometric approach to particle interactions remo…

This isn't really my specialty (string theory), but it's close enough "next door" that our conferences tend to have speakers on this topic on a regular basis. (There's a lot of overlap in individual researchers, too.)

I'm not going to try to one-up the article's non-expert description, but it's worth emphasizing that this isn't a "bold new idea of the week". (Rare among science journalism, I know.) This is a longstanding research program with a substantial number of contributors that's been making clear, gradual progress for a decade or two.

Re: A Jewel at the Heart of Quantum Physics

#47

Post by tgb »

rational_me wrote: post #44
has2k1 wrote: post #33

Earlier quoted context omitted.

It is possible that Gravity as we know it is an illusion. For example, the Newtonian take on Gravity was that it was a force. That according to Einstein was illusory, Gravity was really a geometric manifestation due to the curvature of space-time. With that take Gravity as we know it is different from the Gravity as was once known. However the Newtonian view that Gravity is a force can and still does facilitate usefu…

>I took QFT some years back and it also went over my head. There is still that mental gap of where the only way you can think about time is via time-(in)dependent wave function. Total bullshit. The wave function is time dependent.

There are multiple ways of writing any equation: http://en.wikipedia.org/wiki/Time-independent_Schr%C3%B6ding...

Re: A Jewel at the Heart of Quantum Physics

#48

Post by bdg »

shadowmint wrote: post #40
bsullivan01 wrote: post #35

Earlier quoted context omitted.

what are your qualifications? No offense meant, but I am trying to see if this is real or not. Quite a few smart people seem excited by it, yet you dismiss it

I think the point here is don't hold your breath. Science like this has to be slow and careful. Sudden magical breakthroughs are vanishingly rare, and this probably isn't one; but it is interesting, and worth getting excited about. .. just don't go throwing your Standard Model quite yet. :)

> your Standard Model

If you don't understand your standard model, it's merely a standard belief.

If you understand it, it can be invalidated and thrown away by the 'magical breakthrough' if it provides evidence.

These things shouldn't be treated as a question of political buy-in into to the model.

Re: A Jewel at the Heart of Quantum Physics

#49

Post by bennyg »

ssivark wrote: post #22
gruseom wrote: post #2

Is anyone here familiar with this work? I would like to hear more about it. At a minimum, this article is very much better than the usual science blog filler—it contains signs of a genuine conceptual breakthrough. For example: “You can easily do, on paper, computations that were infeasible even with a computer before.” That doesn't happen very often! Or this: [T]he new geometric approach to particle interactions remo…

I've been keenly following this area of research and have heard some of the talks and read some papers. I concur with the sketch given by @gaze. 1. The notion of unitarity is a "common sense" rule that implies that you can consistently assign probabilities to possible outcomes in a quantum mechanical experiment ( http://en.wikipedia.org/wiki/Unitarity_%28physics%29 ) 2. The notion of locality states that what happens…

Are the terms they reduce to constant, i.e. are they the same variables like spin or charge, no matter the problem? I'm not a physicist - not even close - but I do love a good mathematically general abstraction across a problem space.

Re: A Jewel at the Heart of Quantum Physics

#50

Post by Panoramix »

gruseom wrote: post #18
redhat-reallyp wrote: post #13

Earlier quoted context omitted.

"it contains signs of a genuine conceptual breakthrough." It contains claims of such signs, which seems to be the point of this fluff piece. Alarm bells should go off when you read statements like this: "...giving up space and time as fundamental constituents of nature and figuring out how the Big Bang and cosmological evolution of the universe arose out of pure geometry." Ah yes, well that solves the mystery, doesn'…

What you're saying makes it sound comparable to a compelling software demo that only works on simplified test cases.

Sort of, except in that analogy people like Dijkstra and Knuth are saying "this is a big deal, let's take a closer look".
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