The Amplituhedron

**Taosaur** · 09-18-2013 09:05 PM

https://www.simonsfoundation.org/qua...antum-physics/

The link is a very lucid write-up of the actual science behind the "time and space are an illusion in a jewel" stories you might have seen bouncing around the last few days.

The advancement is a "jewel-like" geometric object, the amplituhedron, that radically simplifies calculating the probability amplitude of particle interactions. The historical significance is that it achieves that simplicity by discarding the 'common sense' notions of locality and unitarity, which have been central to but problematic for quantum physics up until now.

Indeed, even space-time is not a consideration in constructing the amplituhedron; space-time values in the output emerge from the geometry of the figure. The implication is that space and time themselves are properties arising from static, higher-dimensional geometries.

Personally, I find this discovery to resonate strongly with the notion of eternity expressed in Taoism as the "uncarved block," or in Buddhism by the model of Indra's Net. Most contemplative traditions, including Christian mysticism, arrive at some notion of unchanging eternity as a foundation and/or flipside to our temporal existence.

**Xei** · 09-19-2013 12:44 AM

Thanks for the really interesting article.

I'm not sure that this falsifies locality; at least, they don't think so. They're just not using it. I really have no expertise though, nor any strong opinions about locality... I wish PhilosopherStoned was still a regular here, to explain things.

I don't think this lends any more credence to notions of "unchanging eternity". That's just as implicit already in any notion of natural law. Obviously, reality changes - things are different after time passes. But we abstract unchanging patterns from these, like chemistry, or gravity, or the 2nd law of thermodynamics, or quantum mechanics, or the standard model. The 'amplituhedron' is no different in this respect.

**Taosaur** · 09-19-2013 03:33 AM

Originally Posted by Xei

Thanks for the really interesting article.

I'm not sure that this falsifies locality; at least, they don't think so. They're just not using it. I really have no expertise though, nor any strong opinions about locality... I wish PhilosopherStoned was still a regular here, to explain things.

The doubts about locality and unitarity are a standing issue arising from other findings. The significance here is that this is the first successful model to operate without them, and it just happens to work a couple orders of magnitude more efficiently than models including locality. Like you, though, I have no comprehensive understanding of the field; I'm mainly going by the article.

Originally Posted by Xei

I don't think this lends any more credence to notions of "unchanging eternity". That's just as implicit already in any notion of natural law. Obviously, reality changes - things are different after time passes. But we abstract unchanging patterns from these, like chemistry, or gravity, or the 2nd law of thermodynamics, or quantum mechanics, or the standard model. The 'amplituhedron' is no different in this respect.

From the end of the article, with a quote from the senior researcher:

Beyond making calculations easier or possibly leading the way to quantum gravity, the discovery of the amplituhedron could cause an even more profound shift, Arkani-Hamed said. That is, 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.

“In a sense, we would see that change arises from the structure of the object,” he said. “But it’s not from the object changing. The object is basically timeless.”

Most of the reporting on this research has taken the "time and space are illusions" angle, which is by no means proven just by the success of this model, but it looks like where the researchers would put their money. It's only obvious that reality appears to change from our perspective.