From: "JACK L. URETSKY (C) 1996; HEP DIV., ARGONNE NATIONAL LAB, ARGONNE, IL 60439" <JLU@hep.anl.gov>
Date: Thu, 18 Jul 1996 13:52:32 -0500 (CDT)
Hi all-
Lowell Herr writes:
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The "real world" racing examples throw in variable difficult to control.
Last summer in our Project PHYSLab, one teacher actually made some
pavement and took a portion of a auto tire and used a force probe to pull
a portion of the tire across the surface of the homemade road. As
expected, static friction was indeed greater than the kinetic friction.
Of course there was not the usual heating of the tire and road as occurs
when a car goes into a slide. Conclusion - Static friction is greater
than kinetic friction when the variables are carefully controlled and
this is certainly an important aspect of science.
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To which I add the supporting comment:
Experimental physics is a subtle enterprise, and many fine
experimenters have been led astray by confounding effects. The
received wisdom seems to be that when you discover that everyone else
in the world has been wrong over a period of generations, do the following
exercise:
1. Pour yourself a glass of your favorite beverage;
2. Sit down and exult over your superior understanding of nature;
3. Get a good night's sleep while enjoying your great discovery;
4. Get to work and figure out what it takes to make the rest
of the world correct.
Regards,
Jack