3 ms·

The 1G in this case is the acceleration towards your target star system at 10m/s^2 until you are half way, then decelerating at the same rate until you arrive.

The 1G in this case is the acceleration towards your target star system at 10m/s^2 until you are half way, then decelerating at the same rate until you arrive. The fact that this also produces liveable conditions is just a nice side effect of a 1G ship.

AnimalMuppet 5y ago
But does that get you to the Orion Nebula in 15 years? Or do you have to accelerate all the way to do that? (And then you get to wave briefly at the Nebula as it goes cruising by at a significant fraction of the speed of light?)
- Johnny555 5y ago
  Or do you have to accelerate all the way to do that That's what "1G" means in this concept, you're always accelerating at 1G (9.8 m/sec^2) On the first half of the trip you're accelerating toward the destination, on the second half, you're decelerating at 1G. https://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration https://en.wikipedia.org/wiki/Space_travel_using_constant_ac...
  - AnimalMuppet 5y ago
    The graphic in that article is what I wanted. My point was that, due to the highly non-linear time cost, it takes much less time to travel from Earth to X if you accelerate the whole way, rather than accelerate half the way and decelerate the other half. I wanted to know which way gorgoiler used to compute the subjective time. And, thanks to your link, now I know.
- numpad0 5y ago
  Subjectively in decades due to relativity by constantly accelerating, objectively in a millennia or worse. Wonder how to get around interstellar obstacles though, changing courses would be plain impossible
  - Johnny555 5y ago
    Large interstellar objects are, well, large, so you can see them well in advance and just steer around them. changing courses would be plain impossible You can steer by vectoring your acceleration. It would take about 3 days for a 1G ship to travel from the Earth to the Sun, so it wouldn't add much time to the journey to steer around an object the size of the sun. Ideally you'd identify those objects so far in advance that it would take little course correction to go around them. Smaller objects like asteroids that are too small to see in time to avoid would need to be absorbed by the shielding or destroyed or pushed away by some other method. At near relativistic speeds, this would obviously be a non-trivial problem to solve, but hey, you have unlimited energy to solve it.
    - AnimalMuppet 5y ago
      But the faster you go, the more the galaxy is Lorentz contracted from your frame of reference, and therefore the denser the stars are, so dodging gets harder. Also, they're coming at you faster, so you have less time to dodge.
      - WJW 5y ago
        > and therefore the denser the stars are, so dodging gets harder. Not sure this is true, since the stars also get "smaller" and therefore harder to hit. Also, while you have less time to dodge you also don't have to dodge "as much" since your vast speed means you move through any zone quite quickly and therefore don't have much time to heat up/get irradiated. You can probably pass by a star relatively closely as long as you are moving fast enough. (From a heat/radiation perspective, solar wind particles might still mess you up good)
        AnimalMuppet 5y ago
        The stars only get smaller in the direction you're traveling. Perpendicular to that (that is, in the direction you have to dodge), they don't change no matter what your velocity is.
- gorgoiler 5y ago
  Relativity means that by the time your space kids are on to the second generation of space labrador, you’ll be there. To a static observer, 1000 generations of labrador will have been bred back on Earth.

AnimalMuppet 5y ago

But does that get you to the Orion Nebula in 15 years? Or do you have to accelerate all the way to do that? (And then you get to wave briefly at the Nebula as it goes cruising by at a significant fraction of the speed of light?)

Johnny555 5y ago
Or do you have to accelerate all the way to do that That's what "1G" means in this concept, you're always accelerating at 1G (9.8 m/sec^2) On the first half of the trip you're accelerating toward the destination, on the second half, you're decelerating at 1G. https://en.wikipedia.org/wiki/Space_travel_using_constant_acceleration https://en.wikipedia.org/wiki/Space_travel_using_constant_ac...
- AnimalMuppet 5y ago
  The graphic in that article is what I wanted. My point was that, due to the highly non-linear time cost, it takes much less time to travel from Earth to X if you accelerate the whole way, rather than accelerate half the way and decelerate the other half. I wanted to know which way gorgoiler used to compute the subjective time. And, thanks to your link, now I know.
numpad0 5y ago
Subjectively in decades due to relativity by constantly accelerating, objectively in a millennia or worse. Wonder how to get around interstellar obstacles though, changing courses would be plain impossible
- Johnny555 5y ago
  Large interstellar objects are, well, large, so you can see them well in advance and just steer around them. changing courses would be plain impossible You can steer by vectoring your acceleration. It would take about 3 days for a 1G ship to travel from the Earth to the Sun, so it wouldn't add much time to the journey to steer around an object the size of the sun. Ideally you'd identify those objects so far in advance that it would take little course correction to go around them. Smaller objects like asteroids that are too small to see in time to avoid would need to be absorbed by the shielding or destroyed or pushed away by some other method. At near relativistic speeds, this would obviously be a non-trivial problem to solve, but hey, you have unlimited energy to solve it.
  - AnimalMuppet 5y ago
    But the faster you go, the more the galaxy is Lorentz contracted from your frame of reference, and therefore the denser the stars are, so dodging gets harder. Also, they're coming at you faster, so you have less time to dodge.
    - WJW 5y ago
      > and therefore the denser the stars are, so dodging gets harder. Not sure this is true, since the stars also get "smaller" and therefore harder to hit. Also, while you have less time to dodge you also don't have to dodge "as much" since your vast speed means you move through any zone quite quickly and therefore don't have much time to heat up/get irradiated. You can probably pass by a star relatively closely as long as you are moving fast enough. (From a heat/radiation perspective, solar wind particles might still mess you up good)
      - AnimalMuppet 5y ago
        The stars only get smaller in the direction you're traveling. Perpendicular to that (that is, in the direction you have to dodge), they don't change no matter what your velocity is.
gorgoiler 5y ago
Relativity means that by the time your space kids are on to the second generation of space labrador, you’ll be there. To a static observer, 1000 generations of labrador will have been bred back on Earth.