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SithRevan
08-30-2007, 05:07 PM
Well that might have no been the best title in the world for this thread but I couldn't think up anything else.

Anyway to get to what I made this thread about. I just recently discovered a link that I found a little odd. I know (now) that reletivity dictates how fast we can go in the universe and that it doesn't matter how much power we put behind something but more how we do it that really counts. That still doesn't mean though we can't bend the rules a little to make something go as fast as light or faster. What I'm talking about is this here (http://science.slashdot.org/article.pl?sid=07/08/17/1153252), it was an experiment done by a German Physicist that involved "Microwave Photons" and "Quantum Tunneling." Now supposedly this German Physicist broke the speed of light with this experiment. He was able to sucessfully and I quote "'instantaneously' move microwave photons between two prisms that were set exactly 3 feet apart faster then light."

So what does this mean? I don't know. Maybe we can move faster then light using quantum tunneling.

Anyway I'd like to hear your opinions on this as it just seems to good to be true to me.

Also, I'm interested in what Achilles has to say about this. I know disproving these types of things based on relativity is his cup of tea.:xp:

swfan28
08-30-2007, 06:41 PM
As you probably know, theory of relativity has not been succesfully extended to the quantum scale. In fact quantum mechanics often gives very different predictions than the theory of relativity when it comes to describing the same system of particles in a microscopic scale. Quantum tunneling means that a particle appears to penetrate a "potential barrier" that it could not pass by the laws of classical physics or theory of relativity. According to the quantum mechanics, a particle can be simultaneously in several positions. For a "non-infinite potential barriers", there is a chance that a particle appears on the other side of the barrier and it can seemingly move through it faster than light. This is a well-known phenomenon and it is observed in nature for example in radioactive alpha decay. There are also other examples of seemingly faster than light exchanges of "information" in quantum mechanics. Certain processes can produce pairs of particles that are "bound" to each other so that if the spin of one particle changes, the other will also change. The "information" of the changing spin appears to get from one particle to other faster than light even if the particles are far from each other.

The quantum tunneling can't be used to travel faster than light though because it is random. There is a probability for the tunneling to happen, but it cannot be controlled. Not even information in the form of electromagnetic waves can be transferred through tunneling because parts of it will "penetrate the barrier" at random. This effectively prohibits even theoretical use of tunneling for faster than light travel.

I know these things are difficult to describe but I'm looking forward for a discussion about this topic.

Achilles
08-31-2007, 04:55 AM
Also, I'm interested in what Achilles has to say about this. I know disproving these types of things based on relativity is his cup of tea.:xp: :D
As swfan28 points out ToR's influence on the quantum scale is unknown (to the best of our current knowledge, the two scales operate on different sets of principles). I'll have to defer to his expertise regarding what this means for quantum physics, but since you "paid" to hear a ToR rant from me, I'll remind you that as soon as anyone tried to apply FTL travel to a living human being or a fancy space ship, very bad things would happen. At least according to the theory of relativity. :)

Jvstice
08-31-2007, 05:26 AM
I've read some quantum physics books for entertainment a few years back.

I'd be surprised if this specific scientific principle worked for more than sending information. Photons are massless particles. If you send a massed object bigger than subatomic size through such a process, mass would approach infinite. If you weren't careful you'd run into danger even doing the experiments with real humans & ships. This is akin to folding of space. correct?

swfan28
08-31-2007, 06:48 AM
Originally Posted by Jvstice
Photons are massless particles. If you send a massed object bigger than subatomic size through such a process, mass would approach infinite.Are you talking about tunneling or accelerating particles near lightspeed now? Tunneling is perfectly applicable for massed particles also and alpha decay is a perfect example of this. The relativistic mass does not present a problem for tunneling of massed particles because the particle does not actually move when tunneling. It exists in many places simultaneously according to it's wave function. Due to the very short DeBroglie wavelength of macroscopic particles their chance of tunneling is practically zero however.

SithRevan
08-31-2007, 10:46 AM
:D
As swfan28 points out ToR's influence on the quantum scale is unknown (to the best of our current knowledge, the two scales operate on different sets of principles). I'll have to defer to his expertise regarding what this means for quantum physics, but since you "paid" to hear a ToR rant from me, I'll remind you that as soon as anyone tried to apply FTL travel to a living human being or a fancy space ship, very bad things would happen. At least according to the theory of relativity. :)
Well then lets hope that relativity's law does not ever apply on a quantum scale.:D

One other thing I'm interested in is this, since you were talking about space ships and space travel, is the "Alcubierre Drive (http://en.wikipedia.org/wiki/Alcubierre_drive)." I don't know if it's possible or not but from what I can see (and what I can understand) if we were to have enough power and the materials needed to make this work I think it would. We may be unable to control it once we got it going but we'd be essentially travel at FTL speeds... or at least travel suedo-FTL speeds considering the ship would not actually move.:D

swfan28
09-02-2007, 05:10 PM
Originally Posted by SithRevan
One other thing I'm interested in is this, since you were talking about space ships and space travel, is the "Alcubierre Drive." I don't know if it's possible or not but from what I can see (and what I can understand) if we were to have enough power and the materials needed to make this work I think it would. We may be unable to control it once we got it going but we'd be essentially travel at FTL speeds... or at least travel suedo-FTL speeds considering the ship would not actually move.Now this is very interesting... I'm no expert in the field of general relativity but I don't see why this absolutely could not work at least theoretically. It seems that all metrics of the space time that feature this kind of Alcubierre bubbles and are solutions to the field equations of general relativity require exotic matter with negative energy. While that sound impossible the cosmologists are detecting evidence of exotic form of energy called dark energy which has some rather peculiar properties such as generating negative pressure. Maybe negative energy density is also possible. At least it cannot be theoretically ruled out. Unfortunately according to the article a general class of Alcubierre metrics seem to violate the uncertainty principle too and if that turns out to be a mathematical property of all such metrics then I believe it proves Alcubierre drives impossible. I'm definitely going to read more about this.