"This Quantum Theory Predicts That The Future Might Be Influencing The Past"

[HugoVirtuoso]

https://www.sciencealert.com/this-quantum-theory-predicts-the-future-might-influence-the-past

Spooky, isn't it? This could mean more ideas for PosChengband, surely!

For the future - when I find more interesting articles like this one and the other one, I'll try to keep it together in one thread.

[Therem Harth]

This seems really hard to prove, seeing as essentially all experimental science is based on forward causality.

Edit: I would swear I've heard of this before as "advanced photons" that effectively travel backwards in time, but searching is turning up no relevant results, and "time" isn't supposed to matter for individual photons anyway because relativity. IDK.

[Pete Mack]

It doesn't seem to contradict any ordinary physics: phase velocity is already allowed to travel faster than light, and faster than light travel is equivalent to time travel according to special relativity.

[Patashu]

Layman, but I think time travel is 'allowed' specifically when it doesn't carry any information back.

[jupiter999]

Our 3D self is just a "hologram" of "yet another" higher level of our 4D true self

[Pete Mack]

Layman, but I think time travel is 'allowed' specifically when it doesn't carry any information back.

Yep. "Phase velocity" is exactly such a phenomenon.
Faster-than-light travel is forbidden because it is equivalent to time travel under the theory of relativity. Time travel is forbidden because it's paradoxical: if it were possible, we'd already know because it would have "already" happened. (The universe would also be hopelessly unstable.) It makes for great humorous SF: see Kage Baker and Charlie Stross. But there's just no chance it's real.

[AnonymousHero]

Faster-than-light travel is forbidden because it is equivalent to time travel under the theory of relativity. Time travel is forbidden because it's paradoxical: if it were possible, we'd already know because it would have "already" happened. (The universe would also be hopelessly unstable.) It makes for great humorous SF: see Kage Baker and Charlie Stross. But there's just no chance it's real.

Well, except for multiverses or closed time-like curves. Multiverses trivially allow time travel because you're really just extending an existing timeline when you travel back in time. If you just spawn a new universe if you travel back in time then there's no grandfather paradox.

(Also, I think it depends a bit on exactly what you mean by "travel". As long as no information is transmitted, entanglement pretty much allows particles to 'interact' instantaneously... only you can't use it to transmit information.)

[Patashu]

Here's a good discussion on closed timelike curves and how they might actually work in reality:

https://www.scottaaronson.com/democritus/lec19.html

[Ingwe Ingweron]

Ford Prefect is laughing at all of you.