[tedunangst]

The comparison isn't very good. Anyone telling the Wright brothers flight was impossible didn't have science on their side. All they had to do was look out a window and see a bird flying to know that. I suspect "that's a hard problem" morphed into "flight is impossible" over time because it makes their story more inspirational.

[TomasSedovic]

Also, there's a difference between "using quantum entanglement to communicate faster than light" and "communicating faster than light".

If I understand it correctly, it's theoretically feasible to achieve the the latter (in effect).

While it's impossible to send information at speeds that exceed c, it should be possible to bend the spacetime (e.g. using worm holes) so that the information would appear to have traveled faster than light.

[hugh3]

While it's impossible to send information at speeds that exceed c, it should be possible to bend the spacetime (e.g. using worm holes) so that the information would appear to have traveled faster than light.

Wormholes, it should be noted, are "possible" in only a rather remote sense. If you put a wormhole into the equations of general relativity and say "Hey general relativity, is this a valid solution to your equations" it'll say "Uhhh, sure!". But then if you ask it how to arrange masses in order to actually get that solution it'll say "Haha, you can't do that."

[TomasSedovic]

Can you please expand on that last line? I read it two ways and I'm not sure which one you mean.

Does the "you can't do that" refer to getting a how-to-build-a-wormhole recipe from general relativity, i.e. "I can't tell you how to build one, go figure it out yourself".

Or is it more along the ways of "You don't have a worm hole? Well too bad, there's no way you can create one. But hey, it could totally hypothetically exist."

If it's 1) then we could possibly build one (or find it in the universe somewhere) and GR just doesn't tell us how. If it's 2) then we know it can't even be created.

[hugh3]

I'm not an expert on wormholes, but: general relativity will tell you how space curves for any ol' distribution of mass you like, and it tells you there ain't no distribution of mass you can arrange that'll give you a wormhole.

On the other hand, we still don't understand the whole relativity/quantum-mechanics overlap region, so it's possible that whatever new physics are waiting for us in that regime just might include wormholes.

I'm really reluctant to say that, though. Many people seem to jump straight from that to drawing pictures of wormhole-hopping spaceships. Sorry, it's very very very very very very very unlikely to happen.

[TomasSedovic]

I didn't know that you couldn't arrange mass in any way to get a wormhole.

I've never been able to figure out in my (broken, I'm sure) mental model how you could create a wormhole but I suspected that the people who actually understood physics did know.

Thanks a lot, man. Interesting stuff.