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A Jewel at the Heart of Quantum Physics

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Physicists have discovered a jewel-like geometric object that dramatically simplifies calculations of particle interactions and challenges the notion that space and time are fundamental components of reality.

“This is completely new and very much simpler than anything that has been done before,” said Andrew Hodges, a mathematical physicist at Oxford University who has been following the work.

The revelation that particle interactions, the most basic events in nature, may be consequences of geometry significantly advances a decades-long effort to reformulate quantum field theory, the body of laws describing elementary particles and their interactions. Interactions that were previously calculated with mathematical formulas thousands of terms long can now be described by computing the volume of the corresponding jewel-like “amplituhedron,” which yields an equivalent one-term expression.

“The degree of efficiency is mind-boggling,” said Jacob Bourjaily, a theoretical physicist at Harvard University and one of the researchers who developed the new idea. “You can easily do, on paper, computations that were infeasible even with a computer before.”

The new geometric version of quantum field theory could also facilitate the search for a theory of quantum gravity that would seamlessly connect the large- and small-scale pictures of the universe. Attempts thus far to incorporate gravity into the laws of physics at the quantum scale have run up against nonsensical infinities and deep paradoxes. The amplituhedron, or a similar geometric object, could help by removing two deeply rooted principles of physics: locality and unitarity.

“Both are hard-wired in the usual way we think about things,” said Nima Arkani-Hamed, a professor of physics at the Institute for Advanced Study in Princeton, N.J., and the lead author of the new work, which he is presenting in talks and in a forthcoming paper. “Both are suspect.”

Locality is the notion that particles can interact only from adjoining positions in space and time. And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one. The concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature.

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions. The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.

“It’s a better formulation that makes you think about everything in a completely different way,” said David Skinner, a theoretical physicist at Cambridge University.

The amplituhedron itself does not describe gravity. But Arkani-Hamed and his collaborators think there might be a related geometric object that does. Its properties would make it clear why particles appear to exist, and why they appear to move in three dimensions of space and to change over time.

Because “we know that ultimately, we need to find a theory that doesn’t have” unitarity and locality, Bourjaily said, “it’s a starting point to ultimately describing a quantum theory of gravity.”
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The rest of the article can be read here.

Can someone dumb this down for me a little bit? I read the article but isn't the most layman friendly piece in the world.
 
It's way above my head but here's what I've been able to gather.

They've found a more efficient method to calculate how particles interact (the current method uses Feynman diagrams). But the new method only works in a simplified quantum field theory which does not apply to the real world. Locality and unitarity (along with space and time) are not assumed as fundamental principles of the theory but can be derived as emergent properties.

This could be the first step towards something revolutionary or it might be just another dead end in physics, it's way too early to tell.
 
I only have a rudimentary grasp of it myself, but I find this very interesting. Thanks for sharing :thumb_up:
 
Take a ball and a concave bowl. Flip the bowl upside down so the bevel is facing you and place the ball on top. Push the ball off the bowl and watch it until it drop off the table, a local point found in an open system. Now the chance you flip the bowl and drop the ball inside you would watch the ball roll off the sides, up and down until it becomes static in a closed system. Now say the ball was dropped to hard in a closed system out of the pipe dream and then BAM! You're perfectly enclosed system has jumped the fence. This manifest equation will can be applied to anything from psychology, computers.. hell even meteorology. It's one big ploy for quantum physicist to be like, "It's all for the sake of quantum monotony, YO!"

Recall big theory of everything? It's huge
Work is just the natural way of the universe, man.
 
sweet article , so what they are saying is nature/reality/universe at its core is governed by geometry rather than mathematics or physical laws that appear to be governing the surface level of nature/reality/universe

also the physicists are heading towards a new understanding which might turn locality and unitarity as obsolete concepts when understanding gravity at a quantum level

also the locality and unitarity have been already described , however in simpler terms ,

locality means two objects have to be nearby each other to affect each other , example - a ball and a bat have to be near each other if the bat wants to affect the ball

unitarity - any situation or experiment can have only one possible outcome , even if thousands of probabilities exist , example - the bat hits the ball only on one side, right or left even if its probable that it could hit it on both sides

thus with the new theory the bat might be able to affect the ball even if million miles apart and hit it on all sides and in all directions as multiple outcomes to a situation or experiment are possible now

hopefully i did'nt get it wrong :lol: , also i know nothing about quantum physics

edit : i am reading the article now i read the quote and thought that was all of it , the article is really long so perhaps i may not be reading it , in any case whatever i have written above might be wrong , good luck people

edit again : so i could'nt really read the article right now because i gotta head somewhere yet from what i gather the physicists are just trying to say - its crazy people the universe is a crazy place , have fun and trust in fractals for they are the good deliciousness that pours when the nectar flows :twisted: ,
 
It's not that locality and unitarity are obsolete in this theory. It's that they're not assumed as constraints from the start, instead they're derived as emergent properties.
 
Thanx for sharing, alert! A truly fascinating read. The Amplituhedron, presenting a glimpse into a new view into heretofore hidden mysteries, revealing an eye candy of quantum mechanism, as it interrelate to reality (as we struggle to understand it's enigmatic nature). Emergent space-time, amplitude of gluons, emergent quantum mechanics... 8)

I bookmarked the link and and am most intrigued to study this phenomenon further. The fact that the geometric structure/equation is crystalline or jewel-like, is a lovely bonus, indeed!!! :thumb_up:

SUSY 2013 Conference: Video Archive

Website of the International Conference SUSY 2013
susy2013.ictp.it susy2013.ictp.it
 
To pass on some information that I have learned from other physicists recently...

In quantum field theory, calculating the many pathways between two particle configurations can sometimes be very difficult. For this reason, quantum field theorists develop all sorts of tricks that simplify calculations, though only for specific problems. The amplituhedron is such a trick. If it does simplify a QFT calculation, then it probably only works for very specific configurations. Even so, it has not yet been applied to a real QFT problem, from my understanding. So far, the amplituhedron calculation tool only works for a very specific QFT problem which is actually a toy problem to begin with. By "toy problem", I mean it is an overly simplified problem with no real applications.

So, from what I have learned about QFT and amplituhedrons from others, amplituhedrons may not end up being that useful in simplifying QFT calculations and, if they are, they will probably only apply to an extremely limited scope of QFT problems.
 
Interesting. Glad hixidom bumped the thread as I missed it last month.

Reading the article and starting to watch the video brother RS linked to, had me thinking about Terrence McKenna the whole time... or nearly so.

As many of you probably know, the great bard of Hyperspace spoke often about a crystaline object at the end of time. He spoke about this teleological "strange attractor" that he felt all of our existence was being inexorably drawn to. While it is common to deride ol' TM's Timewave Zero stuff and the novelty theory laid over the I Ching he used to come up with his 2012 meme (esp. since 2012 has come and gone)... it does bear some thought that this latest cutting edge of QFT is rather strikingly in line with Terrence's tryptamine inspired descriptions of singularity.

Obviously, TM was no physicist, and even as gifted as he was at describing ineffable things, he probably would not have imagined this Amplituhedron.

Also, as many here have pointed out, this new conception is mostly still just a computational trick... and one that seems to have been created by data fitting no less. (The old Texas Sharpshooter logical fallacy)

Still, it makes me a bit giddy to find that some serious scientists--who are also taken seriously--find that eliminating locality and unitarity as assumptions is the direction to be exploring. This, in light of the fact that TED censored some talks and disowned TEDx WestHollywood earlier this year for basically exploring themes of non-locality. I am curious how Sheldrake views this amplituhedron...

HF
 
I think what science desperately needs is more philosophers handling the problems that we are facing. One that has an understanding of the mathematics. And basically a continuation of the old days in which philosophers like Plato, Pythagoras (the only ones i know :D) used mathematics and reason to grasp methaphysical problems.
 
Infectedstyle said:
I think what science desperately needs is more philosophers handling the problems that we are facing. One that has an understanding of the mathematics. And basically a continuation of the old days in which philosophers like Plato, Pythagoras (the only ones i know :D) used mathematics and reason to grasp methaphysical problems.
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In my limited experience I have have found two broad categories of scientists.

1) Those who approach the world with skepticism.
2) Those who approach the world with awe.

I think the world needs more scientists in the second category.
 
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