Relativity's role in forbidding FTL Information Transfer

  • Thread starter Thread starter Swamp Thing
  • Start date Start date
  • Tags Tags
    Ftl Information
Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
Sign up Log in
4 replies · 2K views
Swamp Thing
Insights Author
Messages
1,062
Reaction score
819
Imagine a (purely hypothetical) situation where someone proposes a scheme that exploits non-classical, nonlocal interference effects to transfer information between Alice and Bob. Apart from the accuracy and plausibility of the quantum mechanical part of the paper, would it be necessary for the author to address conflicts with relativity?

In other words, how important (in peer-reviewed contexts) is the role of considerations such as "Ah, but then Alice could be traveling at a relativistic velocity, enabling her to receive a message from Bob's future, and she could right away send a signal back into Bob's past that would somehow prevent Bob from later sending his message to Alice in the first (?!) place!" Would the author have to address such matters? Would a typical referee request her to do so (assuming that the referees couldn't find any other flaw)?
 
Physics news on Phys.org
Every superluminal information transfer that works in all reference frames implies that you can send messages to your own past. That is not completely ruled out, but it is rarely considered physical. A theory that proposes superluminal information transfer should be able to answer what happens if you do that, unless it explicitly breaks relativity (e. g. by introducing a preferred reference frame, such that superluminal information transfer is not possible in all reference frames any more).
 
Well, if I were refereeing the paper, I would expect some section addressing such a matter. I would be shocked if the authors were so bold as to claim a violation of relativity.
 
I also would suspect a reviewer to expect some reference to relativity in a paper discussing ftl communication. I'd expect either maths providing an explanation of how it does not violate relativity. If it is expected to deviate from the rules of relativity, I would expect an explanation as to why that's okay, and what experiments can be done to prove it or what experimental results it fixes.

When Einstein proposed GR in the first place, he did so knowing that it violated the accepted maths of the universe. He knew that it would solve the existing problem that Newtonian gravity did not work on Mercury, as well as making a prediction that you could use the sun to bend light from behind it.

I always handwave physics explanations for sci-fi by adding stuff that was discovered in the time between now and the story's "present." I just wrote a section where a researcher cracked the light speed barrier, I explained away causal violations by building on the uncertainty principal and giving particles fuzziness in time in an asymmetric way (It's more likely they'll travel forwards in time, but the chances of going backwards are explicitly not zero.) This allows my universe to self-correct.
 
Last edited:
newjerseyrunner said:
I explained away causal violations by building on the uncertainty principal and giving particles fuzziness in time in an asymmetric way

Could this be developed into a scientifically valid and consistent viewpoint on decoherence, I wonder?