Dear Dr. Staff: Why does popcorn pop in a
microwave oven? I read in a science magazine that things called
quasars in outer space emit microwaves, but I held a bag of popcorn up
to the sky one night for a whole hour, and none of it popped. Why do
microwaves make popcorn pop only in an oven?
Dear Popper: You've absolutely right that both microwave ovens and quasars produce microwaves. But the two things produce very different microwaves.
In order to answer to your question, one should consider exactly
what microwaves are. Everyone knows what waves are, and every wave
has a particular size, called its wavelength. ``Micro'' means
``small''; microwaves are waves with small wavelengths. Corn kernels
are small things, too, which is why they get popped by small waves.
However, each kernel has its own unique size, which corresponds to the
wavelength that can pop it. Microwave ovens work by sensing the size
of the popcorn kernels you've placed in them (that's why the kernels
have to sit in the oven for a couple of minutes before they start to
pop-- But quasars don't know how big your popcorn is-- You may have seen old popcorn poppers in antique stores that used
hot oil or hot air to pop corn--