3 ms·
How do you stop so you don't go whizzing past Alpha Centauri at near light speed? :)
by roter 2y ago
How do you stop so you don't go whizzing past Alpha Centauri at near light speed? :)
- dandanua 2y agoAn intelligent alien race, living there, will be able to catch you, don't you watch sci-fi movies? The real question is from what you can get 4.13e+19 Jouls, required to reach Alpha Centauri in about 9 years of traveler's time.
- aeve890 2y ago>An intelligent alien race, living there, will be able to catch you, don't you watch sci-fi movies? The aliens on alpha Centauri are 12 ft tall blue hunter-gatherer humanoids. Not much of a help for your parking problems.
- jdawg777 2y agoIf you use fission, Uranium 235 has 83.14 TJ/kg. So you would need about 500 metric tons of it.
- tokai 2y agoif you can accelerate at 1g you can also decelerate at 1g
- thfuran 2y agoOnly if you can turn around or vector your thrust.
- alhadrad 2y agoI was wondering about this too—it's super interesting! Did you create this? Could you add graphs showing acceleration and deceleration? Also, this might be a dumb question, but how does mass factor into the energy calculations? I would love to see graphs that include the multiple stages of travel (acceleration and deceleration) as well as the mass of various kinds of fuel required for different propulsion systems such as chemical rocket, nucular etc.
- ANewFormation 2y agoRelativistic mass increases are an observed effect. So if you're on the relativistic starship (as these are usually called) your mass does not change as your relative velocity does. But for an at rest observer, your ship's mass would approach infinity as its speed approaches the speed of light. This is the reason the ship would never be observed as hitting the speed of light. In practical terms this is also why particle accelerators can't just infinitely accelerate the particles - their apparent mass exponentially increases and so too does the amount of energy required to continue to accelerate them.
- Rhapso 2y agoI really really wish they would call it "apparent mass". It is entirely an observer effect. Its entirely "that ship throws propellant out the back but they don't end up going as fast as Newton thinks it should, so it must have more mass than we think"
- whatshisface 2y agoIf there are many objects moving in many directions, you won't be able to find a reference frame in which the mass of the system is equal to the sum of the rest masses of the objects.
- Rhapso 2y agocorrect. This is not a contradiction. A reference frame is definitionally a point from which you would measure an "apartment mass". The rest mass isn't relevant to a reference frame where that mass isn't at rest. This is true at all scales.
- mpclarkson 2y agoHey, I created this and yes I want to include charts if you want to decelerate too so you don't go flying past. I knocked out this initial version yesterday afternoon and already planned to add this. Might see if I can do it today.
- headcanon 2y agoyeah, I'd love to see an option to include a deceleration step and what the time debt looks like from there.