I know that no mass can move through space faster than light but I read somewhere recently that very remote galaxies might be receding faster than light relatively to us. In that case, a spaceship in Poul Anderson's
World Without Stars would not be able to jump directly into such a galaxy. It would have to accelerate toward light speed, then jump into a galaxy receding at near light speed, then accelerate again in order to jump into an "FTL" galaxy. On such a basis, how much of the universe would immortal spacemen be able to explore? Is the universe infinite? But are their lifespans potentially infinite? At some stage, such speculations go beyond the possible. It would have been good to read more about this particular fictional future.
5 comments:
Kaor, Paul!
I've also read that, as time passes, galaxies will recede so far from each other that they will pass beyond reach of being detected at all.
Except, of course, those cases where two galaxies "collide"/merge with each other, as will happen in the remote future with the Milky Way and Andromeda galaxies.
Ad astra! Sean
There are a few proposals for using magnetic fields to interact with plasma like the solar wind, or interstellar gas, so as to slow an attached space ship relative to the plasma. Call it a magnetic parachute.
In the case of the solar wind, since the wind is moving away from the sun at a few 100 km/s this would push the spacecraft away from the sun.
If you can somehow get a spacecraft up to several % of lightspeed for STL interstellar travel, such a device could be used to slow the spacecraft as it approached a destination star.
Given a jump drive like in "A World Without Stars", you could jump to the far side of a destination galaxy so cosmic expansion leaves you moving toward that galaxy and use the magnetic parchute to slow yourself relative to the galaxy. I don't see any reason one could not make further jumps to beyond where cosmic expansion is moving galaxies away from the Milky Way at greater than light speed.
Of course this assumes such a jump drive is *possible*. If it is, it would also make time travel possible.
Kaor, Jim!
I've seen some roughly similar proposals discussed at the CENTAURI DREAMS website.
But FTL of some kinds appeals much more to me than time traveling.
Ad astra! Sean
Tho' as a historian-manaque I find time travel appealing too...
From Sean M. Brooks:
Kaor, Mr. Stirling!
I can't deny time traveling for real would also be fascinating.
Ad astra! Sean
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