[Ars] Can we craft a theory in which space and time aren’t assumed to exist?

[Space Lynx]

Can we craft a theory in which space and time aren’t assumed to exist?

In some versions of quantum gravity, time itself condenses into existence.

arstechnica.com

I just read this article from Ars Technica, this is very interesting stuff to think about. I am regular watcher of Startalk podcast with Dr. Neil DeGrasse Tyson, would be interesting to hear his take on stuff like this. I think I have heard him talk about almost everything but not this.

@Drone thoughts?

 

[Drone]

I want to quote Roger Penrose (iirc, he invented spin networks)

"I'm more concerned with what you might call gravitizing quantum mechanics than quantizing gravity."

Einstein's General Relativity is drop dead gorgeous , it'd be extremely annoying to "quantize" such beauty. I really hope that theory of everything is not quantum gravity. And I'm not a big fan of string theory. Some versions say that our Universe is 26 dimensional others say that it's 11 or 10 dimensional. Twistor theory sounds more reasonable and can be tested (in principle).

Many physicists now believe that space-time is a secondary notion and it comes about from something else. And there's a reason for that. All those theories are just .. theories. Astronomers believe that if we'll have a high resolution picture of CMB (cosmic microwave background) we can test twistor theory, cosmic strings and all those exotic things. Unfortunately there's no such equipment atm so we need to wait when they build one. Others think that we can find answer in giant particle accelerators, and we don't have one yet, LHC is way too weak for that purpose.

 

[Grog6]

Supercolliders:

When we get to the moon, we can just set up a shaded plastic pipe, with steering magnets, around the whole moon, add a small amount of LN2 and LHe, and it will be comparatively cheap to run.

Lunar surface atmosphere isn't a totally hard vacuum, but the difference isn't going to collapse a 12" dia pex tube, lol.
( the difference between 10^-11 torr and 10^-15 torr isn't a lot of molecules)

Seeing a large turbopump running in the open would be a trip to see.

The LHe and LN2 would only get heated by the work the magnets are doing, so the cooling requirements are low.

It also gets it off planet, just in case we cause a black hole, lol. (j/k)

 

[FordGT90Concept]

“One can think of this process in GFT condensate cosmology as being analogous to steam,” he says. “Steam is a phase in which the entities which constitute all of space—or atoms of space as we call them—can find themselves condensing into water, which is our analogy for space-time.”

Oriti's PhD student Isha Kotecha says that a lot of their work involves thinking about classical gravitational systems in terms of statistical thermodynamics, the branch of physics that deals with heat and temperature. “There are two reasons we can think of gravity thermodynamically” she told Ars. “Firstly, the laws of classical black hole mechanics already hint at a relationship between gravity and thermodynamics, suggesting that more generally we can think of space-time as a thermodynamic system. This is what we call the thermodynamics of gravity.

Makes sense to me. Also sounds like it could lead to an elegantly simple formula which, judging by E=mc^2, the universe prefers. String theory is everything but simple.