81–90 of 500 posts
Earlier quoted context omitted.
Well that depends on the ejection velocity. If you could shoot it out at close to speed of light, you'd need much less.
If you were to shoot it out at close to the speed of light, you'd knock the Earth out of its orbit.
I had no idea you could achieve relevant amounts of time dilation so "easily" with relatively small (1m/s) of constant thrust - such that interstellar travel becomes somewhat viable provided you can continuously accelerate for the entire trip. Googling it, it would take approximately three years of observed time for a traveller to get to alpha centauri at 1g. Could any somewhat-plausible technologies (fusion etc) get…
One gee over the course of months is insane . Even if you converted the entire "fuel" reaction mass directly into momentum, you're still carrying tens or hundreds of thousands of tons of fuel for any remotely habitable spacecraft. And no engine has perfect mass conversion. Matter-Antimatter has been simulated to be maybe sixty percent efficient, fusion is around 17%, nuclear pulse propulsion a surprising 7%, fission…
This makes me think of the Quen Ho in Vernoe Vinge's "Zones of Thought" universe.
Don't forget to accelerate in the opposite direction (move it down) once to see the starlight shift out of visual range! It's fun until about 95% of c then there is just blackness.
I had no idea you could achieve relevant amounts of time dilation so "easily" with relatively small (1m/s) of constant thrust - such that interstellar travel becomes somewhat viable provided you can continuously accelerate for the entire trip. Googling it, it would take approximately three years of observed time for a traveller to get to alpha centauri at 1g. Could any somewhat-plausible technologies (fusion etc) get…
It isn't possible without a magic reactionless drive; it might even require a zero-energy drive since the kinetic energy is huge and needs to come from somewhere. The rocket equation kills you. A reasonable fusion rocket would require an enormous (like an entire planet worth) to continuously accelerate to relativistic speeds. Antimatter drives are the only option and still require large amounts of reaction mass since…
Earlier quoted context omitted.
Every proton would have the energy of a baseball. It's bananas. Granted, space is really empty, but it's not that empty, somewhere around a hundred atoms per cubic meter. Your ship might look like a very, very long shooting star. Probably dialing the speed down a touch would be worth it for whatever your shielding material is, but who knows? We're talking miracle engines here. I think in the "Valkyrie" ship-on-a-stri…
I like that old Arthur C Clarke novel, The Songs of Distant Earth[0], where they travel with an ablative shield in front made of ice, and they can make new shield segments by finding planets with water. [0] https://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth
Though I can't say much without giving away spoilers.
A great read if you are a sci-fi fan!
Lots of intelligent comments and I'm just here finding it scary.
Don't forget to accelerate in the opposite direction (move it down) once to see the starlight shift out of visual range! It's fun until about 95% of c then there is just blackness.
Earlier quoted context omitted.
While traveling near c, I believe you'd be receiving Earth transmissions from approximately the same time you left, Earth clocks would appear to slow down to a crawl. But if you land on another planet and change reference frame to be more "stationary" again relative to Earth, I think a massive amount of Earth time would suddenly appear to have elapsed very quickly during the process of slowing/landing because of the…
There is no payback day in time dilation.