Sean Carroll: Experimental Validation of Quantum Mechanics Interpretations and Emergent Spacetime

00:00:00.000 | - Even outside of quantum computers,

00:00:03.840 | some of the theories that we've been talking about,

00:00:06.480 | what's your hope, what's most promising

00:00:09.320 | to test these theories?

00:00:11.200 | What are kind of experiments we can conduct,

00:00:14.300 | whether in simulation or in the physical world,

00:00:17.700 | that would validate or disprove or expand these theories?

00:00:22.320 | - Well, I think there's two parts of that question.

00:00:25.960 | One is many worlds, and the other one

00:00:27.360 | is sort of emergent space time.

00:00:29.440 | For many worlds, there are experiments ongoing

00:00:32.000 | to test whether or not wave functions spontaneously collapse.

00:00:35.100 | And if they do, then that rules out many worlds,

00:00:38.720 | and that would be falsified.

00:00:40.800 | If there are hidden variables,

00:00:42.600 | there's a theorem that seems to indicate

00:00:45.480 | that the predictions will always be the same,

00:00:47.880 | as many worlds.

00:00:49.120 | I'm a little skeptical of this theorem.

00:00:50.480 | I'm not completely, I haven't internalized it.

00:00:52.080 | I haven't made it in part of my intuitive

00:00:54.200 | view of the world yet.

00:00:55.040 | So there might be loopholes to that theorem.

00:00:56.480 | I'm not sure about that.

00:00:57.840 | Part of me thinks that there should be

00:00:59.400 | different experimental predictions

00:01:00.760 | if there are hidden variables, but I'm not sure.

00:01:03.200 | But otherwise, it's just quantum mechanics all the way down.

00:01:06.480 | And so there's this cottage industry in science journalism

00:01:10.800 | of writing breathless articles that say,

00:01:13.360 | quantum mechanics shown to be more astonishing

00:01:15.960 | than ever before thought, and really,

00:01:17.400 | it's the same quantum mechanics we've been doing since 1926.

00:01:20.880 | Whereas with the emergent space time stuff,

00:01:22.840 | we know a lot less about what the theory is.

00:01:25.360 | It's in a very primitive state.

00:01:27.560 | We don't even really have a safely written down,

00:01:31.120 | respectable, honest theory yet.

00:01:33.000 | So there could very well be experimental predictions

00:01:35.360 | we just don't know about yet.

00:01:36.600 | That is one of the things that we're trying to figure out.

00:01:39.240 | - But for emergent space time,

00:01:41.320 | you need really big stuff, right?

00:01:43.640 | - Well, or really fast stuff, or really energetic stuff.

00:01:46.960 | We don't know.

00:01:47.800 | That's the thing.

00:01:48.760 | So there could be violations of the speed of light

00:01:52.580 | if you have emergent space time.

00:01:54.920 | Not going faster than the speed of light,

00:01:56.820 | but the speed of light could be different

00:01:58.460 | for light of different wavelengths, right?

00:02:01.440 | That would be a dramatic violation of physics as we know it,

00:02:04.300 | but it could be possible.

00:02:05.960 | Or not, I mean, it's not an absolute prediction.

00:02:07.880 | That's the problem.

00:02:09.040 | The theories are just not well-developed enough yet to say.

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Sean Carroll: Experimental Validation of Quantum Mechanics Interpretations and Emergent Spacetime

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