Einstein's special relativity beyond the speed of light


by bohm2
Tags: einstein, light, relativity, special, speed
bohm2
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#1
Oct10-12, 11:27 AM
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Not sure if this was posted but this seems like an interesting paper. Then again, I'm not well read in this topic to judge their arguments:
We propose here two new transformations between inertial frames that apply for relative velocities greater than the speed of light, and that are complementary to the Lorentz transformation, giving rise to the Einstein special theory of relativity that applies to relative velocities less than the speed of light. The new transformations arise from the same mathematical framework as the Lorentz transformation, displaying singular behaviour when the relative velocity approaches the speed of light and generating the same addition law for velocities, but, most importantly, do not involve the need to introduce imaginary masses or complicated physics to provide well-defined expressions. Making use of the dependence on relative velocity of the Lorentz transformation, the paper provides an elementary derivation of the new transformations between inertial frames for relative velocities v in excess of the speed of light c, and further we suggest two possible criteria from which one might infer one set of transformations as physically more likely than the other. If the energy–momentum equations are to be invariant under the new transformations, then the mass and energy are given, respectively, by the formulae and where denotes the limiting momentum for infinite relative velocity. If, however, the requirement of invariance is removed, then we may propose new mass and energy equations, and an example having finite non-zero mass in the limit of infinite relative velocity is given. In this highly controversial topic, our particular purpose is not to enter into the merits of existing theories, but rather to present a succinct and carefully reasoned account of a new aspect of Einstein's theory of special relativity, which properly allows for faster than light motion.
Einstein's special relativity beyond the speed of light
http://rspa.royalsocietypublishing.o...rspa.2012.0340

Physicists extend special relativity beyond the speed of light
http://phys.org/news/2012-10-physici...tvelocities:v/

Extending Einstein's Theory Beyond Light Speed
http://www.sciencedaily.com/releases...1010092742.htm
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Naty1
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Oct10-12, 03:29 PM
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Lots of math turns out not to have a physical basis....

"We are mathematicians, not physicists, so we've approached this problem from a theoretical mathematical perspective," said Dr Cox. "Should it, however, be proven that motion faster than light is possible, then that would be game changing.
"Our paper doesn't try and explain how this could be achieved, just how equations of motion might operate in such regimes."
time may tell if such math applies to our universe.

It appears only the abstract is available for free...
bohm2
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Oct10-12, 03:52 PM
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There were a few posts here also:

http://physics.stackexchange.com/que...speed-of-light

bcrowell
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Oct10-12, 06:14 PM
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Einstein's special relativity beyond the speed of light


I find it hard to work up any motivation to worry about a paper that's published in a low-impact, paywalled journal, not available on arxiv, and appears to be a rehash of a topic that's already been carefully studied and found to be uninteresting.

The possibility of defining superluminal frames of reference (as opposed to just describing superluminal particles) has been studied for a long time. There is a no-go theorem described by Vieira, which says that it only works in n+n dimensions. It doesn't work in 3+1 dimensions. The physics.SE thread discusses the fact that this objection also applies to Hill and Cox's work.

Vieira, An Introduction to the Theory of Tachyons, 2011, http://arxiv.org/abs/1112.4187
Physicist50
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Oct12-12, 02:52 PM
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Quote Quote by bohm2 View Post
If, however, the requirement of invariance is removed, then we may propose new mass and energy equations, and an example having finite non-zero mass in the limit of infinite relative velocity is given. In this highly controversial topic, our particular purpose is not to enter into the merits of existing theories, but rather to present a succinct and carefully reasoned account of a new aspect of Einstein's theory of special relativity, which properly allows for faster than light motion.
I'd like to see what those equations are that allow us to travel faster than c! Also, what's non-zero?
zeesh
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Jan11-13, 01:16 AM
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Phys.org article: http://phys.org/news/2012-10-physici...elativity.html

Link to the paper: http://rspa.royalsocietypublishing.o....0340.abstract

Any comments from the Physics gurus?

My knowledge reagarding SR is somewhat limited. So your comments would be appreciated.

Thanks.
Bill_K
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Jan11-13, 06:47 AM
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Nothing of interest. Except it does serve to illustrate how much popular attention you can garner with the words "faster than light".

If you like, here's the full paper.
A.T.
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Jan11-13, 08:41 AM
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I didn't read it, just looked at Fig. 4. If I understand correctly:

v : Velocity of frame B relative to frame A
u : velocity in frame B
U : velocity in frame A

Is that right?

Lets say a rocket fires a missile from it's nose launcher. The missile moves at u = 0.5c relative to the rocket. But In a frame where the rocket moves at v=4c the missile is slower than the rocket (U < 4c) and stays behind it, or destroys it right after launch.

How is that resolved?. Is the entire rocket mirrored in the frame where it moves FTL? Negative length contraction?
bcrowell
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Jan11-13, 10:29 AM
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We discussed this back in October: http://www.physicsforums.com/showthread.php?t=642823 The paper is wrong.
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Jan11-13, 10:35 AM
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Here is a recent note that points out what Cox and Hill did wrong:

Andréka, 'A note on "Einstein's special relativity beyond the speed of light" by James M. Hill and Barry J. Cox,' http://arxiv.org/abs/1211.2246

The criticism is essentially the same as in this thread and the physics.SE thread: the idea only works in n+n dimensions, not 3+1.

But Andréka, like Cox and Hill, doesn't seem to realize that this was all settled way back in 1986 by Recami.

Obviously the RSPA doesn't have very high standards or very knowledgeable reviewers if they accept this kind of paper, which is both wrong and wrong for reasons that have been known and published in the literature for 25 years.
jtbell
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Jan11-13, 10:39 AM
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Threads merged.
zeesh
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Jan11-13, 12:00 PM
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Quote Quote by bcrowell View Post
Here is a recent note that points out what Cox and Hill did wrong:

Andréka, 'A note on "Einstein's special relativity beyond the speed of light" by James M. Hill and Barry J. Cox,' http://arxiv.org/abs/1211.2246

The criticism is essentially the same as in this thread and the physics.SE thread: the idea only works in n+n dimensions, not 3+1.

But Andréka, like Cox and Hill, doesn't seem to realize that this was all settled way back in 1986 by Recami.

Obviously the RSPA doesn't have very high standards or very knowledgeable reviewers if they accept this kind of paper, which is both wrong and wrong for reasons that have been known and published in the literature for 25 years.
Thanks a lot for your comments and the link.

It seemed somewhat suspicious so I thought to confirm the results with you guys. :)


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