Gödel's solution to Einstein's field equations (2021) (opens in new tab)

Also, any kind of instantaneous communication.

Unless the theory of relativity is superseded by something quite radically different.

That's assuming the current model of physics is true for all time. The current model of physics which cannot account for 95% of matter in the universe.

There was a time when the current model of physics couldn't allow for traveling to different planets.

Never say never.

In reality it’s debatable, but within the logic of the fiction universe it holds, yeah?

To be able to move those sorts of distances and arrive at a time comparable to the origins absolute time would require the “time travel” aspect of ftl, right?

I’ve never quite understood why this is so certain.

If I instantly teleported to Alpha Centauri, that wouldn’t put me in the future.

Sure, if I turned a telescope back towards our system and watched Earth, I would see myself wandering around as I was four years ago and then… after four years… I could watch myself step into a teleporter.

This is entirely consistent and in no shape, way, or form would this let me get super rich on the stock market.

You could only ever know information from your present or your past.

Imagine a hypothetical universe with a maximum speed ‘s’. The creatures in this universe could develop relativity and everything, the same as us. But what if ‘s’ is the maximum speed of sound in the gas that fills this toy universe? What if the creatures are all blind and use only sonar to get to know their world? Would travelling faster than ‘s’ be violating causality somehow? Or would it simply be the same as a supersonic plane, leaving a sonic boom behind it?

Having said all that, I very strongly suspect that FTL will never be possible. However, I don’t agree that it would result in time travel if it were possible.

Spooky action at a distance doesn't need to be a thing.

Retroactive causality implements the same functionality without requiring information to propagate faster than c.

Indeed, in fact indirect evidence suggests that Sir Isaac, the source of that quote, probably had more intellectual horsepower than anyone until von Neumann.