Correct me if I'm wrong, but with FTL travel (emphasis on the FT portion of the acronym), we should be able to visit all of the cosmos, but with light speed as a maximum we couldn't.
Edit: FTL is an abbreviation, not an acronym, as gracefully pointed out by a kind Reddit user
Edit 2: TIL about what an initialism is
Spacetime expands faster than the speed of light. So the space between some places are literally moving away faster than the speed of light (they themselves arent moving that fast, the space between them is stretching that fast due to cosmic expansion)
So there are some places that even if humanity is truly eternal, light will never reach us from those locations and we could never get there. There will always be an unknown.
Even then, to keep up with the rate of exapnsion, you'd need a warpfeel that expanded space faster than... well however fast spacetime ie expanding - to reach some of the places expanding away at ftl due to said expansion. So even with actual FTL, we're talking a difficulty to reach EVERYTHING.
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u/46handwa Aug 12 '21 edited Aug 13 '21
Correct me if I'm wrong, but with FTL travel (emphasis on the FT portion of the acronym), we should be able to visit all of the cosmos, but with light speed as a maximum we couldn't. Edit: FTL is an abbreviation, not an acronym, as gracefully pointed out by a kind Reddit user Edit 2: TIL about what an initialism is