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In books of science fiction (Asimov) I saw the fancy idea of a "jump" over a space-time interval, (i.e. at superluminal velocity and for a VERY SHORT time). The result was landing in another region of the galaxy, that during a human life one has no chance to reach.

Can someone imagine that this fictional idea can become, some day, realistic?

Or, putting in negative form, are we DOOMED to remain exclusively in the neighborhood of our solar system? Given that our Sun is a yellow star (not young) and continuously aging, in a couple of millions of years the life on our solar system will become impossible.

I don't deal with general relativity, s.t. my question is surely naïve. Though, an answer like "light-velocity cannot be surpassed", would be trivial.

DanielSank
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Sofia
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In principle, general relativity allows space-time to have non-trivial topology (wormholes) or dynamics (Alcubierre drive) that could be used to 'cheat'. However, it is very likely that such things do not exist (they violate some 'reasonable' assumptions about the universe, but without a predictive theory of quantum gravity, no one can say for sure); but even if they did, it is doubtful that they could be used for travel.

So no, we're stuck with the universal speed limit $c$. However, thanks to time dilation, that's not as much of a problem as one might think - you just cannot do real-time communications or round trips (more precisely: you'd 'time-travel' to the future - the well-known twin paradox).

Logistics would be a real problem if you ever wanted to establish a galactic civilization, but imo it is a great opportunity for 'hard' sci-fi.

As long as we're speculating, I can think of 3 different approaches for interstellar travel and colonization:

  • small relativistic rockets, possibly aided by cryonics (which might also help to avoid negative effects of radiation); such ships need heavy shielding at the bow
  • big generational ships, possibly using solar sails (seems that's not realistic for big payloads?), possibly using a big shell made of water and ice as shielding
  • not sending humans at all and going the AI route, possibly using self-replicating robotic ships
Christoph
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