I have only been skimming the phys-l digest of late. It's weird that when
you think you couldn't get any busier, you do. Anyway -- if the following
has already been discussed, I apologize in advance.
In the most recent _Physics Teacher_, there appeared a one-page article
which described how one could use a pan of marshmallows in a microwave oven
to determine the speed of light. The method involves measuring the
distances between hotspots or more-cooked places on the top of the layer of
marshmallows. It is asserted that this distance is the wavelength of the
microwaves. I am having trouble understanding why this is so. It seems
reasonable that a standing wave may be set up inside the microwave. It also
seems reasonable that the hot spots would correspond to the anti-nodal
points. What I don't get is why the distance between the anti-nodes should
be a wavelength. One-half wavelength makes more sense to me as the distance
between consecutive antinodes. Help me, someone, please.
Thanks,
++++++++++++++++++++++++++++++++++++++++++++++++++++++
Cherie 8-) | ==>NOTE: Our area code has changed from 317 to 765!|
Cherie Bibo Lehman Physics Teacher
cblehman@ecn.purdue.edu West Lafayette Jr-Sr High School
(w)765-775-1300 1105 N. Grant St.
(fax)765-775-1375 W. Lafayette, IN 47906