[gavmor]

Here's a great video explaining how, due to relativity, FTL travel can cause grandfather paradoxes: https://youtu.be/an0M-wcHw5A?si=RYFGOmQOlaC2t0bM

Edit: in short, not all reference frames can agree on the order of events, and FTL events propogate "backwards" between some reference frames.

[david-gpu]

That doesn't mean that light (causality) couldn't be faster, right? You could increase the speed of light (causality) as much as you want and wouldn't run into any paradox.

[gavmor]

What does it mean to increase the speed of causality? This seems like asserting that we can add as many tick marks to the axis as we like, since the only universal unit of measurement is a velocity's percentage of C.

If we imagine something going faster than the speed of causality, we're simply misconcieving the properties of space.

[layer8]

With respect to what, though? One light-second would still be one light-second. The sizes of atoms and elementary particles probably also are a function of that. (We don’t know that, but it seems plausible.)

[simonh]

You'd be able to use an FTL laser to shoot your own grandfather as a baby. Plus you'd be able to receive an FTL broadcast of what's going to happen tomorrow.

[coldtea]

Mainly in the sense that you can create an amp that goes to 11.

[MattPalmer1086]

Right. The speed limit itself is arbitrary.

[MattPalmer1086]

Nice video, thanks for posting.