4 ms·
Interstellar space contains neutral hydrogen atoms. Hitting a spaceship, they would produce electromagnetic radiation. When the collision speed goes past about
by nine_k 9mo ago
Interstellar space contains neutral hydrogen atoms. Hitting a spaceship, they would produce electromagnetic radiation. When the collision speed goes past about 0.25c, the radiation becomes hard gamma rays which are dangerous to living things, and cannot be efficiently shielded against.
At this speed, the time dilation is slightly above 3%, so you're still not going to reach even Alpha Centauri in one human lifetime, or maybe you barely can.
- gpm 9mo agoAlpha Centauri is only 4.2 light years away. 0.25c is definitely enough to reach it. You could even do a round trip in only your adult years.
- MichaelZuo 9mo agoA trip there to do… what? There likely won’t be any planet better than the very low bar of Mars for human habitation, in fact maybe even worse due to binary perturbations.
- gpm 9mo agoWhy do people row across the ocean? If humanity survives to a high enough tech level, someone will do it just because they can...
- andrekandre 9mo ago> A trip there to do… what? to play golf, what else? https://www.youtube.com/watch?v=t_jYOubJmfM https://www.youtube.com/watch?v=t_jYOubJmfM
- deleted 9mo ago[deleted]
- coldtea 9mo agoYeah, if you take the highly unlikely and already lethat 0.25c achievability as a given.
- Dylan16807 9mo agoThat is the context the above comments are talking in. Well, except that you changed below lethal to already lethal.
- tialaramex 9mo agoRight, we are never leaving. We should get comfortable here, and take better care of the only habitable planet, rather than doing insane things and justifying that as "Don't worry, we'll make Mars habitable" and other silliness.
- chasil 9mo agoLife cannot leave, no. A radiation hardened, self healing computer could.
- tosti 9mo agoBut when it returns, would it say 404 or 42?
- tialaramex 9mo agoI think you should assume that the radiation hardened, self healing computer would consider itself alive. But importantly that's not us leaving. Some distant future descendent of humans could have engineered itself to leave, but it's not us and we shouldn't fixate on that distant and unknowable future.
- generic92034 9mo agoWell, things like the eventual expansion of our own star or the probability of a sizeable asteroid/comet hitting earth tells me, that we should at least keep thinking about leaving. Even if the current tech is nowhere near good enough.
- keyringlight 9mo agoEven if we do leave, it's unlikely that we do so for a very long time so taking care of the planet makes sense even if you intend to discard our crib. Similarly in the nearer term if we had a unified goal to colonize a near planet/moon that's still going to take a huge long term effort to do more than the equivalent of putting a tent up on an island off the coast to get that colony established (if it can ever be self-sufficient).