The Solar System: September, AD 15605

[rdanhenry]

Strictly speaking, you cannot avoid time dilation, but I assume what you mean is that if you took a gravbubble from Earth to a nearby star system some 11 light year away, spent a year exploring that system and came back, you'd be about 23 years older, just like the folks at home. This severely limits the usefulness of your fast gravbubble drive unless you use sleeper ships or humans are nigh-immortal and have high boredom thresholds. I wouldn't want to spent years in a cramped spaceship with no outside contact, only to be an old man when we reached our mission objective 40 light years away. This is not necessarily a bad thing, I just wanted to make sure you were aware that avoiding relativity effects in this way hampers rather than encourages exploration beyond the nearest stars. Probably not going to find a habitable world this way (and only very maybe one that can be made habitable with awesome future tech) unless you use one of the outs I mentioned. (Nor does there appear to be any reason why being in a gravbubble should influence relativistic effects.)

Your solar system is starting to look pretty amazing.

[töff]

The idea is that, because the person is not moving within the gravbubble, there's no time dilation. But I'll also admit that I've reintroduced the concept of the ether into that particular future-speculative storyworld. Also, humans are are both near-immortal (advanced med tech) and they have sleeper tech of many sorts available if they want it, including a time-stoppage-by-balanced-supergravity technique. But yes, we travel at the speed of light, without time dilation, is the bottom line. Note that it does take time to accelerate up to the speed of light; but, because you are only moving a near-massless point, and you're not experiencing that acceleration inside the bubble, you can push as hard as you want with your engine. I think the fastest I've used so far was 133g, which reaches lightspeed in 2.5 days. I have a calculator for it here: http://lattice.mysteryandmagic.com/r...#gravityengine

[töff]

Time dilation is a factor of the passenger (and therefore the vehicle) experiencing acceleration up into significantly relativistic speeds. That takes an immense amount of energy, and it also exposes the vehicle (and therefore the passenger) to hazards such as a few molecules of dust hitting your ship with the force of a hydrogen bomb. It's really just not the way to go.

Of course, we don't have gravbubbles or warp drives in real life, so the only practical method of space travel we have in the foreseeable future is extreme velocity, so we'd better learn how to deal with it. The Bussard ramjet, while designed as a fuel-gathering system, has the interesting side benefit of removing space dust from your path.

Of course, science is making incredible theoretical leaps, which usually translate into practical technologies. So maybe we will have warp drive ships or wormhole gates or something equally cool. Heck, we have Kirk's communicator now. With apps! Who'd'a thunk that would become a real thing back when we were eating burgers on TV trays in the late 60s and watching Joan Collins get run over by a truck.