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Keraunophobe's Answer
Thu Nov 06, 2003
Listen in RealAudio 
Hi, I’m Bryan Yeaton for The Weather Notebook. You may have been wondering where our
Brainstormer had snuck off to. Well, he’s back, and has pieced together the answer to our last
Brainstorm. We asked why electrical activity in the air makes your hair stand up, and what was
the machine from your physics class that did the same thing?
Here’s Mark Prevost of Bordelonville, Louisiana:
"The name of the device is a Van de Graaff Generator and your hair has an electric charge and
the static electricity causes your hair to stand on end."
That’s basically the right answer—although some schools use Tesla Coils instead of Van de
Graaffs.
Bill Melton of Lincoln, Nebraska fills us in on the terminology "I believe it’s called an
electro-static charge. When it actually sparks that’s an electro-static discharge"
Mrs Lloyd Whitley explains how the Van de Graaff works:
"It generates static electricity, high voltage but very, very low current and the individual’s
hair all end up having the same charge, like charges repel, therefore, someone’s hair will
stand up."
Craig Honoroff listens on KAWC in Yuma, AZ.
"The negatively charged electrons travel to the farthest points on the person’s body, which
then causes it to repel and since your hair is a very far point that is where the electrons
end up going and so you get like charges repelling each other and so your hair stands on
end."
Correct, although the generator can also cause a positive charge to collect on the metal
sphere, depending on how it is configured.
Thanks to everyone who sent in an answer. For a list of links, go to our website at
www.weathernotebook.org, and click on Today’s Show. We are funded through grants from Subaru
of America, and The National Science Foundation.
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