alt Hacker NewsNo Theory of Everything is going to make realistically testable predictions. That's a problem of the domain, not the theory. The unification energy between the graviton and quantum field theory is on the order of 10^19 GeV, over a dozen orders of magnitude beyond anything we can generate.
We might get lucky that some ToE would generate low-energy predictions different from GR and QFT, but there's no reason to think that it must.
It's not like there's some great low-energy predictions that we're just ignoring. The difficulty of a beyond-Standard-Model theory is inherent to the domain of the question, and that's going to plague any alternative to String Theory just as much.
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I'm far from an expert in this field--indeed, I can but barely grasp the gentle introductions to these topics--but my understanding is that calling string theory a "theory of everything" really flatters it. String theory isn't a theory; it's a framework for building theories. And no one (to my understanding) has been able to put forward a theory using string theory that can actually incorporate the Standard Model and General Relativity running in our universe to make any prediction in the first place, much less one that is testable.
I think that’s highly debatable. For example, dark matter particles with testable properties could be a prediction of a ToE. Or the ToE could resolve the quantum measurement problem (collapse of the wave function) in a testable way.
There's a more basic problem with string theory, which is that it's not a theory. It's a mathematical framework which is compatible with a very wide range of specific physical theories.
About tests of quantum gravity, there have been proposals for feasible tests using gravitationally-induced entanglement protocols:
i mean, a theory of everything should at least make retrodictions, which afaik string theory never got to. if someone wants to point me to where someone solved e.g. the hydrogen spectrum using a string theory, then I will be wrong but very happy
> The unification energy between the graviton and quantum field theory is on the order of 10^19 GeV, over a dozen orders of magnitude beyond anything we can generate.
lol the confidence.
The testable predictions would be at the places where QM and GR meet. Some examples:
1. interactions at the event horizon of a black hole -- could the theory describe Hawking radiation?
2. large elements -- these are where special relativity influences the electrons [1]
It's also possible (and worth checking) that a unified theory would provide explanations for phenomena and observed data we are ascribing to Dark Matter and Dark Energy.
I wonder if there are other phenomena such as effects on electronics (i.e. QM electrons) in GR environments (such as geostationary satellites). Or possibly things like testing the double slit experiment in those conditions.
[1] https://physics.stackexchange.com/questions/646114/why-do-re...