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A comment on Gravity: We might have been getting it wrong. Parent comment

Re:Gravity: We might have been getting it wrong by glofish on Friday January 24, 2020 @04:23PM (#22142601)
TLDR:

  [...] the holographic principle allows physicists to study gravitational systems by projecting them on a boundary

  [...] proved that symmetry is not possible in a gravitational theory if it obeys the holographic principle.

  [...] meaning that symmetry would not be possible in quantum gravity.
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Re:Gravity: We might have been getting it wrong by Khaine on Friday January 24, 2020 @05:25PM (#22143013)
PBS Space Time have done a number of episodes on the holographic principle[1]

I strongly recommend anyone interested in physics check out the channel

[1] https://www.youtube.com/watch?v=klpDHn8viX8

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Re:Gravity: We might have been getting it wrong by hinkley on Friday January 24, 2020 @06:26PM (#22143348)
By inference. this means we trust the holographic principle so thoroughly that we don't even consider that it could be the unbalanced part of this equation.

Is that true?

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Re:Gravity: We might have been getting it wrong by TheOtherHobbes on Friday January 24, 2020 @07:42PM (#22143756)
AdS/CFT fell out of string theory. It's only holographic in the sense that in some circumstances you can summarise an n=dimensional system using n-1 dimensions - not in the literal sense of using the kind of optical transforms that make visual holography possible, but in the more abstract sense that all of the information in some spaces ends up on a notional surrounding boundary.

The AdS universe is basically a mathematical toy for physicists to play with. It doesn't correspond with the physical structure of the real universe. There's a hope that it might correspond to some kind of mathematical meta-structure that defines physical laws.

This article suggests that's very unlikely.

Personally I wouldn't be surprised if AdS/CFT turned out to be a dead end - probably like supersymmetry - and the real structure of quantum gravity turned out to be completely different and unexpected, and not a Conformal Field Theory at all.

But IANAP, so I may well be wrong about that.

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Re:Gravity: We might have been getting it wrong by RandomBacon on Friday January 24, 2020 @05:32PM (#22143045)
For people on a mobile device:

> TLDR:

> the holographic principle allows physicists to study gravitational systems by projecting them on a boundary

> proved that symmetry is not possible in a gravitational theory if it obeys the holographic principle.

> meaning that symmetry would not be possible in quantum gravity.

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Re:Gravity: We might have been getting it wrong by foobar1962 on Friday January 24, 2020 @11:22PM (#22144656)
... if it obeys the holographic principle.
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