3 ms·
This is why there’s ideas like the Bussard ramjet, which may not work but try to work around this problem by using in situ mass-energy. Now I have read that it
by api 2y ago
This is why there’s ideas like the Bussard ramjet, which may not work but try to work around this problem by using in situ mass-energy.
Now I have read that it may be possible to use a powerful magnetic field to assist with slowing down by braking against the interstellar medium, which helps.
The Avatar films have (in spite of very derivative plots) fairly realistic (at least physics wise) interstellar ships. They accelerate using beamed laser propulsion from the Sun and use antimatter rockets to decelerate, then repeat this in reverse to come home. One assumes they somehow recharge at their destination but this is not shown. Too bad all that cool tech is in service to humans who decided to be the bad guys from War of the Worlds.
Still traveling that close to c brings up tons of other problems. Collision with a micrometeorite would be like an atomic explosion, and blue shifting of incident and cosmic background radiation would blast you in the head with x-rays and gamma rays. Those problems would demand more mass for active or passive shielding, and you’re already mass constrained.
All things considered it’s way more practical to go slower — which could still be insanely fast e.g. 0.25c — and figure out how to cryosleep or become an AI that can just turn yourself off for the trip. Cryosleep for humans is a brutally hard biomedical problem but way easier than trying to approach the speed of light. There are other multicellular animals that can do it, albeit much simpler ones, so it’s probably possible.
0.25c allowing for acceleration and deceleration gets you to Centauri in around 25 years and to further star systems with promising exoplanets in hundreds of years.
Then there’s generation ships, but that’s the kind of thing Mormons would do. :)
- PaulHoule 2y agoI'd imagine interstellar travelers who have mastered D+D fusion could break the journey down into hops of maybe 10,000 or 100,000 AU looking for large comets or plutoid objects which they could use to replenish their supplies. I'd imagine it would take them 10,000 years or so to make it to the next star system but they might not care if they can live a comfortable lifestyle in the great dark.
- api 2y agoSomething I didn’t think about: there is debate over how empty the space between stars is or whether there are a lot of rogue planets, comets, asteroids, maybe even exotic objects like asteroid or planet mass primordial black holes (these are a dark matter candidate). If the space between stars is not as empty as we imagine it opens other possibilities like flybys and refueling.
- giantrobot 2y agoInterstellar space can be filled with junk yet still be effectively empty because it's so mind bogglingly large. Comets and rogue planets also aren't helpful unless 1) you can see/chart them ahead of time and 2) they're on the way to your destination. The first problem is a big challenge as they're cold, dark, and small. Just finding them to begin with is a giant problem. Accurately charting them is another order of magnitude increase in difficulty. Even tiny error bars in the measure of their proper motion means your spaceship can miss them by millions of miles. Even missing them by a dozen miles is the difference between life and death. Even with a huge catalog of extremely accurate interstellar fuel-capable objects they don't do you any good if they're not on the way to where you want to go. A meandering route to a destination in order to visit refueling stops adds tons of extra complexity and points of failure.
- RajT88 2y agoMight I humbly recommend the disaster of a TV show "The Starlost".
- PaulHoule 2y agoI saw the draft script Phoenix without ashes in an anthology. I ought to look up the show as I'm a fan of trashy SF. (Just read Pohl's notorious Plauge of Pythons)
- shwouchk 2y agoAt sufficiently relativistic speeds, it wouldn’t just be “like” an explosion - you would have instant nuclear fusion at impact.