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This is a relativistic spaceflight simulator which shows what it would look like if you were on a spaceship traveling close to the speed of light. It is loosely based on my original code from 2012 implementing relativistic effects in my game The Polynomial.
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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…
> As an SF writer, it's pretty interesting, though, to think of the weird shapes a society would take when your astronauts are outliving entire civilizations. I guess this all depends on how you define simultaneity. Say I got on a relativistic rocket traveling near c and colonized Planet X in 10 years ship time and say 20,000 years Earth time. I put up my TV antenna as soon as I land, and I'd still be receiving Earth…
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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.
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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
Earlier quoted context omitted.
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…
What if you didn't carry the fuel? Use stationary lasers from your starting point to power your journey half way until you lasers from your destination to slow your craft down.
Great visualization of the unintuitive nature of special relativity. It's kind of mind blowing to realize that if we could accelerate our spaceship at a mere 1G continuously, we could visit the center of the Milky Way in under 20 years (spaceship time), totally do-able in a human lifespan. Of course 27900 years would have passed on Earth, so you wouldn't be able to tell anyone about your vacation.
It's worth saying that 1G is heavy acceleration to maintain, nothing "mere" about it. When you run the numbers the amount of energy involved basically adds up to needing a rocket made entirely of antimatter, and a similar mass of 'normal' matter to react with. Keep in mind that when talking about long-distance journeys in space under any sort of constant acceleration, the numbers are generally in thousandths of 1G.
Can't get it to slow down to a standstill. Is that a bug?
Acceleration vs speed. Adjust the acceleration until the "The ship is flying at X% the speed of light" is almost zero.
Earlier quoted context omitted.
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…
Can you explain why matter-antimatter only has 60% efficiency?
We don’t know how to use all the reaction products for thrust [1].
[1] https://en.m.wikipedia.org/wiki/Electron–positron_annihilati...
Earlier quoted context omitted.
> As an SF writer, it's pretty interesting, though, to think of the weird shapes a society would take when your astronauts are outliving entire civilizations. I guess this all depends on how you define simultaneity. Say I got on a relativistic rocket traveling near c and colonized Planet X in 10 years ship time and say 20,000 years Earth time. I put up my TV antenna as soon as I land, and I'd still be receiving Earth…
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…
Earlier quoted context omitted.
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…
What if you didn't carry the fuel? Use stationary lasers from your starting point to power your journey half way until you lasers from your destination to slow your craft down.
I think the lasers would also need ~10,000 years of fuel, as opposed to ~10 years of fuel if you could somehow figure out how to carry it. But the energy to sustain in either case is probably measured in Dyson spheres, or some fraction of all energy in the universe pretty quickly too.