In July 1820, Danish scientist Hans Christian Oersted published a groundbreaking pamphlet on the relationship between electric current and magnetic fields, effectively kicking off our modern electric age. You may think about electromagnetism every July when you look at your power bill and see how it spikes when your air conditioner is on. In honor of everyone getting zapped by the electric company this month, we've asked Jeopardy!'s Ken Jennings to set us straight on some high-voltage misconceptions about electricity, correcting all of our shocking ignorance. He knows "watts" up. He keeps current.
The Debunker: Are Power Lines Insulated?
If you've ever watched birds sitting idly on power lines, footloose and electrocution-free, you might have inferred that the black coating on the outside of the wires is rubber or some other kind of insulating material. After all, as a nation, we wouldn't be stringing hundreds of thousands of miles of hot electric death across the landscape, would we? Surely we're better than that.
But no, every year, around 128 Americans are electrocuted by overhead power lines. Many are workers who weren't careful enough, and had their ladder or cherry-picker or something brush a live wire. But some are just regular citizens who came across a downed line and had no idea the encounter could be deadly. It was just lying there! It wasn't sparking or jumping around or anything!
The unfortunate truth is that ninety percent of America's overhead power lines have no insulation whatsoever—they're just aluminum and steel and maybe a thin (and non-insulating) black weather coating. Birds are safe, because as long as they're just sitting on the middle of a wire, the electricity has no path from them to the ground. But if they were to set one feathered foot on a grounded pole, ZAP. Kentucky Fried Chickadee. For the same reason, humans should always keep their distance from power lines. If you see a downed line, power companies ask you to stay at least 35 feet away, because even if you never touch the wire, you could get shocked by the ground or tree branches if you got any closer. Even rubber gloves or soles may not make a difference, since household-grade rubber often has additives in it that conduct electricity. The only foolproof insulator? Not being an idiot and steering well clear of downed lines.
Quick Quiz: In his most famous hit, Glen Campbell sang that he was a "lineman for the county" in what Midwestern setting?
Ken Jennings is the author of eleven books, most recently his Junior Genius Guides, Because I Said So!, and Maphead. He's also the proud owner of an underwhelming Bag o' Crap. Follow him at ken-jennings.com or on Twitter as @KenJennings.