Isaac Arthur has put it in a way that resonated with me. If you live in a universe that has FTL, it’s scarier in a lot ways. It means the really dangerous bad guys in the other galaxy can reach you. If you live in a world without FTL, it makes things happen really slowly and over generations. That’s not as fun and exciting, but it also severely limits the amount of bad guys that can get to you.
And any bad guy that can even reach you basically means you’re already dead if they so choose.
Doesn't FTL also imply time travel - which probably isn't a good thing?
I think wormholes and warp sort of get around it by having the FTL traveler moving slower that light in their pocket/hole through space.
SPOILER ALERT: Wormholes and warp drives will not work, cannot work, are not physically possible (even though they are "solutions" to the EFE), would not be feasible even if remotely physically possible.
Not really. But it does imply weird things. Sabine Hossenfelder did a video on this.
FTL means the bad guys have already reached you.
There is also some folks that suggest that they are already here. Including an awful lot of high profile people within the defence sectors.
It means you see nothing interesting then a shockwave and here they are.
And here they were, because FTL travel implies eliminating the distinction between "before" and "after."
Not really: https://www.youtube.com/watch?v=9-jIplX6Wjw&pp=ygUKc2FiaW5lI...
Admittedly, I'm in the awkward position of being an old industrial physicist, so on the one hand I'd need an explanation with a bit more substance, but on the other, it would probably be over my head. The most I was able to get from the video is that maybe quantum gravity will crack the problem.