Tonight I found a link to a fun YouTube video on Facebook. Entitled “Finding the Speed of Light With Peeps”, it’s one of the more imaginative demonstration videos I’ve seen.
This demonstration takes advantage of the fact that microwaves move at the speed of light. So take some of the Peeps left over from Easter (you know, those marshmallow chickens so popular at this time of year) and put them in a microwave without a turntable. Microwave them on low ( so they don’t explode) for about a minute. Microwave ovens have hot spots and cold spots (which I’m sure you know) that correspond to the wavelength. Measuring the distance between cold spots will give you half the wavelength; double that for the wavelength. Multiply that by the frequency (printed on the microwave’s data plate), and you can get a reasonable approximation of the speed of light. The formula is speed = frequency x wavelength.
The video is produced by NPR’s Skunk Bear and is very well done — https://www.youtube.com/watch?v=HwREvdUWSKE&feature=youtu.be
Isn’t science marvelous?