🚀 go-pugleaf

On 17 Oct, 07:32, Pentcho Valev <pva...@yahoo.com> wrote:
> Einsteinians know their criminal cult is eternal but still too many
> references to superluminal signals make them nervous; in such cases
> they stop singing "Divine Einstein" and fill Einstein zombie world
> with the scornful "pfffft hahahahahaha":
>
> http://arstechnica.com/journals/science.ars/2007/10/16/how-a-superlum...
> How a superluminal experiment should be conducted
> By Chris Lee | Published: October 16, 2007 - 03:30PM CT
> "A couple of months ago we reported on an arXiv paper that reported
> superluminal pulse propagation [Nimtz' paper]. The paper was such a
> steaming pile of science that our report amounted to something along
> the lines of "pfffft hahahahahaha." The reason was that the
> researchers did not give a detailed explanation of their experimental
> setup, did not present any data other than a rather vague "about 2ps,"
> and didn't try to make a distinction between the group velocity and
> the phase velocity. To examine these sorts of experiments, let me give
> you a short introduction to the propagation of light. Light has two
> speeds associated with it: phase velocity, and group velocity. When
> Einstein formulated special relativity, he did it using the
> empirically observed evidence that the phase velocity of light was
> constant for all observers. The conclusion was that the phase velocity
> of light in vacuum was the fastest speed possible. Today, I am pleased
> to be able to give an example of superluminal experiments done right.
> In work published in Physical Review A, a group of researchers from
> NIST and the Wuhan Institute of Physics and Mathematics...."
>
> So zombies should learn by rote that in 1905 Einstein postulated the
> PHASE VELOCITY was constant, not the group velocity. If he had said
> the GROUP VELOCITY was constant - then, OK, superluminal signals would
> refute relativity - but fortunately Einstein did not say so. Zombies
> should also know that only superluminal experiments published in in
> Physical Review A matter - superluminal experiments published anywhere
> else deserve, by definition, "pfffft hahahahahaha". Finally, zombies
> should never ask the following question: Can superluminal signals
> refute relativity as implied in textbook problems like the following
> one:
>
> http://isites.harvard.edu/fs/docs/icb.topic193296.files/chap11.pdf
> pp. 41-42:
> 11.6. Train in a tunnel **
> "A train and a tunnel both have proper lengths L. The train moves
> toward the tunnel at speed v. A bomb is located at the front of the
> train. The bomb is designed to explode when the front of the train
> passes the far end of the tunnel. A deactivation sensor is located at
> the back of the train. When the back of the train passes the near end
> of the tunnel, the sensor tells the bomb to disarm itself. Does the
> bomb explode?"
> p. 57: "Therefore, the far end of the tunnel passes the front of the
> train before the near end passes the back, so the bomb explodes. We
> can, however, also look at things in the frame of the tunnel (see Fig.
> 11.53). Here the tunnel has length L, and the train is length-
> contracted down to L/gamma. Therefore, the deactivation device gets
> triggered before the front of the train passes the far end of the
> tunnel, so you might think that the bomb does not explode. We appear
> to have a paradox. The resolution to this paradox is that the
> deactivation device cannot instantaneously tell the bomb to deactivate
> itself. It takes a finite time for the signal to travel the length of
> the train from the sensor to the bomb. And it turns out that this
> transmission time makes it impossible for the deactivation signal to
> get to the bomb before the bomb gets to the far end of the tunnel, no
> matter how fast the train is moving. Let's show this. The signal has
> the best chance of winning this "race" if it has speed c....."
>
> Pentcho Valev

The only unthinking undead on this thread is you.