the further you move away from the bitcoin ledger’s lightcone, the more you will fall out of consensus and easier it is to double spend you without you noticing. Not to mention higher chance of long forks that undo large parts of your ledger history when you go back to earth. It just doesn’t work off world. We would need an L2 protocol or just use something physically scarce, and im not sure gold would be that in space.
Then all communication between the two parties, leaving you with effectively a hard fork. But that doesn’t mean that bitcoin is for earth, only.
If you leave earth with earth-level difficulty, you wouldn’t even be able to continue mining elsewhere anyways. You would have to use something else.
…for 2016 blocks.
You wouldn’t be able to mine a single block, and even if you somehow could grind it out, the difficulty adjustment is capped. It would effectively be stalled.
There’s also the notion that by the time we are traveling far enough that maintaining consensus is difficult, my bet is that the on-chain hardly moves other than for large transfers. Tx rate will not be an issue. L2 and above will continue to be a ledger based on the underlying chain (and its more concrete nature). This seems totally doable. This also assumes no advancement in communications if we are traveling that far. I think something like an ansible is going to be possible *before* FTL is possible. For one, if we can manipulate gravity, we can modulate it. And we’re already listening to it (waves from black holes traveling near the speed of light). Gravitational waves have no speed limit.
If we’re talking fully conscious AGI let’s also entertain the idea that future solutions could exist that escape our current understanding of what’s possible with bitcoin bound by the speed of light.