Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: Wave phase reversal on reflection



It is interesting that all of the responses to this query concern
arguments based upon the need to satisfy certain mathematical requirements
of the wave function. It is my experience that the student asking such
questions is seeking a concrete PHYSICAL MECHANISM behind the behavior in
question. The answer to this aspect of the question will be different for
each different kind of wave phenomenon ( eg: acoustical vs E/M ).

This is a common pedagogical communication problem - we should try to get
more concretely physical in addressing student queries (without prejudice
to the guidance of mathematical models). The student has not yet become
sufficiently jaded into abstract, mathematical model thinking to be
persuaded that they EXPLAIN the physical mechanisms of his concrete,
conceptual questions.

Bob

Bob Sciamanda (W3NLV)
Physics, Edinboro Univ of PA (em)
trebor@velocity.net
http://www.velocity.net/~trebor

----- Original Message -----
From: "Jack Uretsky" <jlu@HEP.ANL.GOV>
To: <PHYS-L@lists.nau.edu>
Sent: Tuesday, April 25, 2000 2:34 PM
Subject: Re: Wave phase reversal on reflection


Remove the boundary. The reflected wave projected past the boundary
must exactly cancel the incident wave in the region beyond the boundary.
Regards,
Jack

Adam was by constitution and proclivity a scientist; I was the same, and
we loved to call ourselves by that great name...Our first memorable
scientific discovery was the law that water and like fluids run
downhill,
not up.
Mark Twain, <Extract from Eve's Autobiography>

On Mon, 24 Apr 2000, SSHS KPHOX wrote:

My colleague asked if there were a good explanatiion for the phase
reversal when a wave reflects from a boundary where the new speed will
be
less and not when going from slow to fast. I don't have one for her.
Can
anyone help?

Ken Fox
AP/IB Physics Teacher
Smoky Hill High School, CO