How to get across the galaxy moving slower than light - in a single lifetime?
All the recent talk on Worldbuilding about the vast energies available to higher-level Kardashev civilizations, the need for 50,000 year message-systems, and so on, got me thinking. With enough energy, wonderful things might become possible in space travel.
The galaxy is 100,000 light years across. Humans live about a century under optimal conditions. The speed of light cannot be exceeded. How do I get a live human from point A to point B 40,000 light years away? Seems an insurmountable problem, no?
Before I get accused of duplicating a previous question on faster-than-light travel, let me clarify: at no point would the ship move faster than the speed of light from the perspective of observers on Earth, nor would this ship use Alcubierre-style drives to warp space.
What I'm talking about are time and space distortions caused by relativistic spaceflight. Not only does time pass more slowly for the ship-board explorer from the perspective of observers at home, but as she accelerates, distances in the direction parallel to the direction of movement appear to shrink. At some point (I think around 70%c from Earth's perspective), distance shrink will make the explorer estimate that she is going at 100%c if she where to assume that distances measured at Earth where correct. At the same time an person on earth would observe the explorer as aging less than one year for every light year she travels.
Recall that the formulas below must be true both from the perspective of a fixed observer and from the perspective of the explorer:
$L=L_0 \sqrt{1-\frac{v^2}{c^2}}$
$t=\frac{t_0}{\sqrt{1-(v/c)^2}}$
The energy requirements to accelerate a ship to this speed would be immense, of course, but a Type II civilization, having $10^{26}$ watts (joules/sec) at its disposal, should have no trouble with this at all.
Would it indeed be possible to travel across the Milky Way in a single lifetime, if you were willing to forsake friends and family?
How would the monstrous time-lag at the homeworld affect a society's willingness to send out explorers?
Where would such expeditions go? What would be a worthwhile destination?
This post was sourced from https://worldbuilding.stackexchange.com/q/9022. It is licensed under CC BY-SA 3.0.
1 answer
It seems like you could do it without even getting close to the speed of light if you could bend space.
The whole "Imagine the universe is a 12 dimensional piece of paper. Fold it in half so that the place you are and the place you want to be are touching. Now punch a hole through the paper so you can travel directly from where you are to where you want to be."
Can space be bent like that? Some people think wormholes work that way, like if space time is all crumpled up. IF that is the case, then you wouldn't have to bend space, just find the place where the crumpling has already brought the two pieces of reality next to each other, and then use a punch drive to move across.
0 comment threads
0 comment threads