Re: [Phys-l] Neutrinos going faster than speed of light?

[curtis osterhoudt <flutzpah@yahoo.com>]

Indeed. ANY traveling-wave phenomenon (including evanescent acoustical waves, my particular subject) can have superluminal (tending to infinite) phase velocity under certain circumstances. It's a totally worthwhile exercise to convince one's self (and present it to good undergraduate students) how that can be, too. 

A quantitative derivation requires some decomposition into shaded plane-waves (or some basis you know how to deal with), but you can qualitatively argue from following, in your mind, how such waves are actually generated. For me, it's a pretty good check on whether I really understand what's going on (always a thoroughly depressing exercise).

 



> ________________________________
> From: alex brown <aesbrown77@yahoo.co.uk>
> To: betwys1@sbcglobal.net; Forum for Physics Educators <phys-l@carnot.physics.buffalo.edu>
> Sent: Saturday, September 24, 2011 10:46 AM
> Subject: Re: [Phys-l] Neutrinos going faster than speed of light?
>
> phase velocity can, but group velocity can't...
>
> --- On Sat, 24/9/11, brian whatcott <betwys1@sbcglobal.net> wrote:
>
> From: brian whatcott <betwys1@sbcglobal.net>
> Subject: Re: [Phys-l] Neutrinos going faster than speed of light?
> To: "Forum for Physics Educators" <phys-l@carnot.physics.buffalo.edu>
> Date: Saturday, 24 September, 2011, 17:38
>
> On 9/24/2011 10:58 AM, chuck britton wrote:
> > I SAID it was naive and the BRIEF reading had me still thinking of a
> > vacuum chamber that had withstood the earthquakes/drifting etc.
> >
> > yikes ;-)
>
> More in the same naive vein: I seem to recall that there is a measurable 
> entity in EM waves that
> has super-luminal velocity: is it phase velocity vs group velocity?
> Gamma rays have wave properties too of course!   :-)
>
> Brian W
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