Star Trek's Warp Drive Not Impossible

Trunks writes "No doubt trying to ride the hype train that's currently going for the new Star Trek film, Space.com has a new article detailing how warp drive may not be impossible to acheive. From the article: '"The idea is that you take a chunk of space-time and move it," said Marc Millis, former head of NASA's Breakthrough Propulsion Physics Project. "The vehicle inside that bubble thinks that it's not moving at all. It's the space-time that's moving." One reason this idea seems credible is that scientists think it may already have happened. Some models suggest that space-time expanded at a rate faster than light speed during a period of rapid inflation shortly after the Big Bang. "If it could do it for the Big Bang, why not for our space drives?" Millis said.' Simple, right?"

Comments

So which is it

[Endo13]

Didn't we just have an article on this exact same thing a few days ago explaining why this is definitely NOT possible?

Re:So which is it

[HeronBlademaster]

The theory is that, at the time of the big bang, space was expanding faster than light, so that one year after the big bang particles would be more than 1 light-year apart from each other.

Just a nitpick... you mean "more than 2 light-years apart from each other". Think of a circle with a radius of 1 light-year...

Re:So which is it

[dpilot]

And that's the whole point... From what can be told, it appears that during the Inflationary Era the universe was expanding faster than light. The only reason that doesn't cause headaches is that space itself was expanding, so the objects in it weren't moving too fast. Only problem with the grandparent post is that he *under*estimated the speed.

Even now it's estimated that less than 10% of the universe is within our light-cone, meaning that 90%+ got away from us, and can never be observed.

Re:So which is it

[Mr_Magick]

I don't understand the physics behind the answer, but yes... photon A can never see photon B traveling away from it at a speed greater then light speed. It has to do with time being dilated for an observer on photon A or B. Light speed is the upper limit that any observable object can travel. Once in your light cone, always in your light cone.

The thing that will really blow your mind, is that an observer from the stationary point (C) sees both of the photons traveling away from it a the speed of light.

LHC

[spud603]

Isn't one of the doomsday theories surrounding the LHC that our section of spacetime will get shoved elsewhere in the universe?

Re:Come on...

[Fred_A]

And don't forget: there is a non-zero chance that the universe WAS created by a 7-foot tall bunny made of spaghetti, used video tape, and lug nuts! Everybody panic!!!

The first rule of the universe is : "don't talk of the Spaghetti Bunny" !
What did they teach you in advanced physics class ?

Re:Simple FTL question

[SomeJoel]

No it would not, the motion of the stick on your end would not propagate instantaneously to the ship.

WP article is much better

[bcrowell]

This seems to be describing the Alcubierre drive. The Wikipedia article is much, much better than the crappy article linked to from the slashdot summary.

A few ideas to keep in mind about general relativity:

The structure of general relativity implies, on fundamental grounds, that to build anything like this would to require godlike mastery over huge amounts of mass and energy. This is because the basic field equation of GR relates the curvature of spacetime to its mass and energy content.

The structure of relativity also implies that any faster-than-light technology will also be a technology for time travel. This is because if two events A and B are separated by a distance x that is greater than ct, where t is the time interval separating them, then there are some frames of reference in which A occurs before B, and some in which B occurs before A.

General relativity does not forbid FTL on a totally generic basis.

A good book on the subject is Time Travel in Einstein's Universe, by Gott. (Yes, it's the same subject as FTL, because FTL is equivalent to time travel.)