[f02a]

Obviously, for the extraterrestrial theory to work, you have to imagine you can warp or fold spacetime to get where you need to go, rather than using a conventional engine. Then the universe gets a bit smaller.

[krapp]

>Obviously, for the extraterrestrial theory to work, you have to imagine you can warp or fold spacetime to get where you need to go, rather than using a conventional engine.

That's fantasy, though. One might as well imagine aliens coming to Earth riding dragons through magic portals, as far as reality is concerned.

For any extraterrestrial theory to work and be plausible as a speculative explanation for real world events, it has to assume the speed of light is an inescapable hard limit on everything, because that seems to be the universe we actually live in.

[klingonopera]

Wormholes can exist on hard and solid physics theories, and people are trying to find out if they can make this work in practical situations.

Therefore, your "fantasy" of them coming to earth through magic portals may not be so far off. Whether or not a dragon makes for a good spaceship remains to be seen...

[postalrat]

I favor the theory that they send out unmanned craft that have the ability to manufacture more craft when they reach a star system and repeat the process. I imagine we might have similar technically within 1000 years or so and might just do it. Then it's just a matter of 100s of thousands of years to visit all systems in our Galaxy.

[akimball]

No, you just need to be patient and/or fast.