Saturday, March 3, 2012

Learning Today: The Electrical Venus, The Leyden Jar, and the Stupid Early History of Electricity

Take a boy. String him from the ceiling by silken threads. Charge him with static electricity. If the boy extends his hands he will attract brass fibers. If you touch him, you'll get an electric shock.

This sounds like the internet's latest improvement on planking. But it was actually an 18th Century experiment that helped forward humanity's understanding of electricity.

(This 'experiment' reminds me of an anecdote about Alexander the Great. Disbelieving reports of a liquid that would burn, the great conquerer covered a boy in 'liquid asphalt' and then set the poor urchin alight. This according to Strabo via Will Durant. Something about science and the torture of young children go together, I guess.)

But we shouldn't leave the electrically-charged boy hanging. What was the deal? In the middle of the 18th century, people knew electricity existed--but not exactly what it was or what it was good for. Legions of peritactic scientist showmen prowled the lyceums of Europe, demonstrating the properties of electricity by doing stupid tricks. They made people's hair stand on end, and amused them by shooting electric shocks from the tips of their fingers. In a popular trick called the Electrical Venus, a woman stood on an insulated platform. An enterprising gentleman leaned forward for a kiss--and received a shock. Humanity is a simple species.

These early magic tricks might seem an ignoble beginning of the study of electricity, but it was this same spirit of exploititive entertainment that introduced educated Europe to the Leyden jar, the first electrical capacitor. The Leyden jar was a way of 'storing' an electrical charge. The jar's inventor Ewald Georg von Kleist, gave himself such a vicious electric shock in the process of making the Leyden jar that he recommended that no one ever try to make a jar ever seriously folks don't try this at home I'm not joking, at the same time as he provided detailed instructions on how to make one. People made Leyden jars in faddish haste, and proceeded to give each other crippling electrical shocks to the amusement of all survivors.

But there was a problem--in the contemporary understanding of electricity, the Leyden Jar shouldn't have worked at all. The theory needed to be changed. And it was this new theory--brought into the world by Mr. 100 Dollar Bill himself, Ben Franklin, which is the reason why we have computers, blogs, and massage wands. But if it hadn't been for stupid parlor tricks like the hanging boy and the electrical venus, we wouldn't have electricity at all.

Almost all the facts in this post come from Patricia Fara's contribution to this week's episode of In Our Time with Melvyn Bragg.

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