Re: phase vs group vel.

[George Spagna <gspagna@rmc.edu>]

The question:

> > Can anyone suggest a good source for a computer demo which depicts the
> > difference between group velocity and phase velocity?

To which Leigh responded:

> Rather than a computer demo, have you a smooth-surfaced pond somewhere
> into which you might drop some rocks? Lacking that, you might just as
> well write a factoid on the board as depict the difference. They've
> seen utterly unphysical things depicted by computers on TV; why do you
> think they will put another depiction into a different class?

If all else fails (absence of ponds, for example) consider a film or video
of a boat moving on smooth water.  Better still, take them for a ride on a
ferry so they can see for themselves the group and phase velocities of the
wake.

George Spagna           **********************************************
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