Message-Id: <v01540b15b166f31543f2@[192.174.2.173]>
Date: Fri, 24 Apr 1998 18:37:44 -0800
To: pinhole@exploratorium.edu
From: pauld@exploratorium.edu (Paul Doherty)
Subject: Re: relativity
Hi Gary
In the Michelson-Morely experiment the source of light and the mirrors and
the receiver are all moving together.
If you do this with sound with speakers and microphones and sound mirrors
you will get interference of the two different paths because the sound is
moving through air, the medium, which is moving relative to the experiment.
If there were a medium, the aether, through which light travelled then you
would get interference of the two light beams in the michelson-morely
experiment.
However there is no interference and this means there is no medium, no aether.
The equation for the doppler shift for light is different from the equation
for the doppler shift for sound due to time dilation. Time dilation
produces a doppler shift (to the red) for light which is from a source
which is neither approaching or receding but just moving past an observer.
This is called the transverse doppler shift.
Paul Doherty