[johnnyanmac]

I won't be the one to solve it, but we thought the sound barrier was unbreakable a few centuries ago. I won't underestimate human ingenuity.

I think more likely is we figure out wormholes. If we can't go light speed we can instead fold space like a piece of paper and reduce the space we need to Traverse. That may or may not be as easy as FTL.

[layer8]

Wormholes imply time travel in much the same way as FTL. There is no escape from this, for very simple geometric reasons.

[johnnyanmac]

If space compression is time travel, sure. It's not like we can't time travel right now (to the future).

I obviously don't have the finer details in line.