General Comments: Phase Velocity

"The phase velocity of a wave is the rate at which the phase of the wave propagates in space. This is the speed at which the phase of any one frequency component of the wave travels. … The phase velocity of electromagnetic radiation may, under certain circumstances, (for example anomalous dispersion) exceed the speed of light in a vacuum, but this does not indicate any superluminal information or energy transfer." -[Kouichi Hirabayashi, 2001,
http://www.mogami.com/e/puzzle/pzl-18.html; emphasis mine.]

"The formula v = c/n calculates the phase velocity of a wave; this is the velocity at which the phase of any one frequency component of the wave will propagate."
[Dispersion(optics), www.wikipedia.com; emphasis mine.]

            There appears to be two contradictory ideas in today's physics writing. Some relativists state that the phase velocity is capable of exceeding the speed of light in vacuo, while other relativists state that it is the group velocity that is capable of such a feat. It is unnecessary, in my view, to dispel this contradiction.
Physicists talk about time of flight and the path length in terms of how long it takes an electromagentic wave to travel a distance through a medium [or, vacuum]. This reference to path length does not refer to the actual flat/spiral path traveled by the photon/energy, but rather the straight-line distance from beginning to the end of the distance measured. "The time of flight is used to measure velocity, from which the mass-to-charge ratio can be determined." ["Time of flight", www.wikipedia.com; paraphrase mine] This concern the time that transpires from the moment a particle issues from a source to the instant in which it is detected on a measuring device. It has nothing to do in fact with the actual path followed by the particle/wave between that distance. It only concerns the abstracted distance demarcated for measurement.
In today's science writing, it appears to be a well-accepted fact that matter-energy events are capable of exceeding and do exceed in fact the defined speed of light in vacuo. The caveat is that such examples of superluminal velocities of matter-energy do not qualify in their modified definition as worthy spacetime/motion events.
"Superluminal communication is the hypothetical process by which one might send information at faster-than-light (FTL) speeds. So far, superluminal communication has not been achieved and scientific concensus is that faster-than-light communication is not possible." [Superluminal communication, www.wikipedia.com] Therefore, any example of superluminal speed of matter-energy that exists is not really superluminal because it is incapable of carrying a communication signal or, something to that effect. The goal posts are effectively moved once again.
Regarding superluminal discussions in relativist physics one comes across questionable word-concepts such as, "wave-like", "space-like", "time-like", etc. There are too many examples to merit a citation.
In general, I have the impression that today's science writing about special relativity is one big "thought experiment", i.e., creative meandering about what possibly could exist were such-and-such to happen, etc. The main concern, it would appear, in treating the apparently confirmed examples of superluminal speeds is that these do not affect the theory of special relativity. Whenever an example of superluminal speed of matter-energy is recognized, the relativists are quick to add "apparent FTL is not excluded by general relativity"; "…this is not quite the same as traveling faster than light, since…"; or, "…so they do not violate special relativity", etc. Too many to list.
In a sense, all recognized examples of faster-than-light travel by matter-energy are employed to "prove" the thesis within special relativity that the speed of light is the maximum attainable velocity by matter-energy. "Apparent superluminal motion is observed in many radio galaxies, blazars, quasars and recently also in microquasars. … The phenomenon does not contradict the theory of special relativity." [Apparent FTL propagation of static fields; www.wikipedia.com] This is but one of the theoretical tricks in today's science writing; and, all one must do is say it is not so.
Basically, since FTL travel cannot carry a signal, then it is really not faster-than-light. "No information or matter can be FTL-transmitted or propagated from source to receiver/observer by an electromagnetic field. …Some processes propagate faster than c, but cannot carry information…". [Apparent FTL propagation of static fields; www.wikipedia.com]
It would appear as though the relativists are saying, any FTL phenomenon of matter-energy cannot be controlled by human beings and therefore does not exist as such. The very fact that the relativists have been able to measure and observe in their own way the FTL examples of velocity of matter-energy surely means that some kind of communication or signal occurred and was observed. It is far too tedious to attempt any unwinding of such examples of circular reasoning in today's science writing by relativists.

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