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+--- Thread: Article A bet against quantum gravity (/thread-14354.html)
A bet against quantum gravity - C C - Jul 10, 2023
https://youtu.be/DkRbNXILroI
VIDEO EXCERPTS: The general feeling amongst physicists, for the last hundred years is that we need to quantize spacetime just as we quantized every other field. But reconciling gravity with quantum theory is one of the great challenges of physics. Thus far we've been hopelessly unsuccessful.
And so I think, we're at a point where we ought to really question whether this drive and this challenge to quantize gravity. Whether that really was the right thing to do.
[...] gravity is different. ... gravity is very much about the arena or the background in which matter moves. So you have this quantized matter which evolves in time and moves in space, and this background spacetime appears to be a necessary part of how we describe quantum theory.
[...] if you quantize the speed of time, what you find is that time becomes frozen. Things don't evolve at all. So this is the immediate problem that people grappled with when they were trying to quantized gravity, and we've been stuck on that ever since.
[...] So a few years ago, after I'd given a talk on the theory, I got into a discussion with Carlo Rovelli, who's one of the founders of loop quantum gravity. And as a result of that discussion, we formulated a bet with 5000 to 1 odds on whether spacetime is fundamentally quantum or not.
Geoff Pennington, who's a leading string theorist, also joined in on the BET. If I win, I will get 5000 items from each of them, maybe some olive oil or a little dram of whiskey maybe, a packet of crisps.
And so what I like about the bets is that they force us to, first of all, make the bet precise in a way that can be tested experimentally, because I think that's important that we can test our beliefs experimentally... (missing details below or link at top)
A bet against quantum gravity
RE: A bet against quantum gravity - confused2 - Jul 10, 2023
If I understand correctly one of the 'problems' arises with entangled particles.
If you measure one and it is (say) 'up' then the other will inevitably be 'down' when you measure it.
If the entangled particles are some distance apart in a space-timey universe there's a time delay between measuring the one and the other having any way to know you've measured it so you could get two 'ups' (or two 'downs'). As far as I know, entangled particles can (experimentally) do their thing regardless of distance so there is a flaw in something somewhere. Possibly the universe is actually flawed and it never will make sense.
Edit..
Like if Schrodinger entangled two cats and put them in 50-50 boxes - if you open the first box and the cat is dead then the second cat can't die. Or something.