By what means might superluminal communication manifest?
Naaa. How do you get anything coherent out of a black hole?Russ: How about negative energy? You could manipulate that and create wormholes, which thus allow superluminal travel.
You overlooked the last option.You forgot one option: it won't.
And yet another option: Low reading comprehension. Oops.You overlooked the last option.
I read some but not all. And I must admit that what I know of wormholes is a little thin, but isn't this guy mixing two theories here? Aren't wormholes just two black holes sharing the same center (singularity)? I'm pretty sure that's what A Brief History of Time says. BTW, anyone ever notice if you lend out that book you never get it back?in a vacuum, not a black hole. In addition to the fact that a perfect vacuum is impossible, there is also the negative energy. There could be 0 positive energy, but tons more of -E.
did you take a look at the site I mentioned above? it talks about the whole plight in detail.(it has a really cool picture of a wormhole too).
Don't the same theories that explain things like quantum teleporation also imply that you can't ever send anything useful that way? The double edged sword of the Heisenberg Uncertainty principle: you CAN get something for nothing, just if you get too much of it it becomes nothing.Perhaps there is some symmetry and logic that can be encoded with in entangled states and then exploited in a Bells Theorem like manner to allow for FTL transmission of useful information.
Absolutely. As far as we know now right now there is no useful information that can be encrypted in entangled states. But that does not rule out the possibility in it entirety. Future knowledge of more complex entangled states MIGHT lead to some type of useful FTL transmission. The key word is might, its all very shaky ground at this point. Before Chuck Yeager broke the sound barrier in the XS-1 in 1947 people thought is was impossible. Sure our equations for relativity and current understanding of modern physics say FTL travel is practically impossible, but there is a slight chance it may work out to be true in the future. You never really know, we are at a position when we can only speculate.Don't the same theories that explain things like quantum teleporation also imply that you can't ever send anything useful that way? The double edged sword of the Heisenberg Uncertainty principle: you CAN get something for nothing, just if you get too much of it it becomes nothing.
I know you know that's an invalid analogy.Before Chuck Yeager broke the sound barrier in the XS-1 in 1947 people thought is was impossible.
I'll give you that. It doesn't seem likely to me though.There are those who feel relativity is not the final say concerning the speed of light. I’m not saying that I feel that the speed of light can or cannot be surpassed. I’m simply saying that we shouldn’t allow our ignorance to rule out the possibility.
I read some but not all. And I must admit that what I know of wormholes is a little thin, but isn't this guy mixing two theories here? Aren't wormholes just two black holes sharing the same center (singularity)? I'm pretty sure that's what A Brief History of Time says. BTW, anyone ever notice if you lend out that book you never get it back?
A wormhole is a geometry of four-dimensional spacetime (for an explanation of spacetime see "spacetime" and "spacetime diagrams") in which two regions of the universe are connected by a short narrow throat. A classical large scale wormhole is a solution of the Einstein's field equations, which governs the curvature of spacetime. The most interesting thing with wormholes is that they could provide relatively easy means of traveling to distant regions of space or even of traveling backwards in time.
That definition is incomplete. It doesn't say how they work or what their properties are. Damn, I wish my dad would give back that book...lemme look around a little.Wormholes are NOT singularities. here's a definition:
So that's where I got the singularity bit. Its still not entirely clear though. Essentially (if I understand correctly), curvature of space-time comes from gravity so doesn't that mean if you want to curve space-time a lot you need a LOT of gravity? IE a black hole? I'm still not clear on how you CREATE a wormhole.In 1935, Einstein and Nathan Rosen wrote a paper in which they showed that general relativity allowed what they called “bridges,” but which are now known as wormholes. The Einstein-Rosen bridges didn’t last long enough for a spaceship to get through: the ship would run into a singularity as the wormhole pinched off.
Ok, negative energy is a quirk of the Heisenberg Uncertainty Principle. It has been detected and DOES exist. But like everything else in HUP, doesn't it disappear in the macro scale? Apparently not:to warp space-time in any other way so as to permit time travel, one can show that one needs a region of space-time with negative curvature, like the surface of a saddle. Ordi-nary matter, which has a positive energy density, gives space-time a positive curvature, like the surface of a sphere. So what one needs, in order to warp space-time in a way that will allow travel into the past, is matter with negative energy density.
And he concludes:One can therefore ask: does quantum theory allow time travel on a macroscopic scale, which people could use? At first sight, it seems it should.
So with our current state of knowledge, time travel on the macro scale *IS* theoretically possible. I wouldn't bet on it either though.Thus the possibility of time travel remains open. But I’m not going to bet on it.
I'm still not clear on how you CREATE a wormhole.
what's a ring singularity?