on 9/26/02 1:01 AM, Michael Tope at W4EF@dellroy.com wrote:
> Group velocity or perhaps more aptly "information velocity" is always less
> than or equal to the speed of light in a vacuum, but the "phase velocity" or
> the speed at which a constant phase point on an electromagnetic wavefront
> progates along the wall of a waveguide can actually exceed the speed of
> light in a vacuum. This is analogous to a wave hitting the beach at a
> slightly
> oblique angle (as opposed to head on).
Thank you for the correction! You are right. Been a long time since I
studied EM wave theory! That was a good refresher course!
73,
Jon
NA9D
-------------------------------------
Jon Ogden
NA9D (ex: KE9NA)
Life Member: ARRL, NRA
Member: AMSAT, DXCC
http://www.qsl.net/ke9na
"A life lived in fear is a life half lived."
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