Can a Penny Dropped From a Building Kill a Pedestrian Below?

May 3, 2007 — -- Have you heard this one? That a penny thrown off the top of the Empire State Building could kill a pedestrian below? Or that it would go through the sidewalk?

Many visitors outside of the famous skyscraper we spoke to had heard all about killer pennies. "Anybody who gets hit by that penny is about to die, 'cause that's a long way for a penny to fall," said one young man. "It could actually go through someone's skull," said another.

Tourists at America's tallest building, the Sears Tower in Chicago, agreed. "If it hit concrete it would probably be smashed into little bits, or just flattened out if it landed sideways," said one man.

"I think it would go through the roof of a car, sink into the cement, or hurt someone," said one woman. "Not a pleasant thought. Don't want to try it, but it would be kind of interesting to find out," she said.

We thought so too, so we asked University of Virginia physics professor Louis Bloomfield about it. "They're thinking of a world without air ... but air resistance is a big deal for little things. It slows down leaves, it slows down raindrops and it slows down pennies," he said.

"The penny is heavier [than a raindrop] but it flutters as it comes down. It's very unstable in the air."

Bloomfield has heard about the myth so often he tackles it in his latest book, "How Everything Works."

"Pennies, they're not aerodynamically stable ... they catch a lot of wind ... basically they're safe," he said.

Safe? Really? We wanted proof. "The ideal thing would be to drop a penny off the Empire State Building and catch it," he said. "But sadly, no building will let us do this because they're all worried about the myth!"

At our request, Bloomfield concocted another test. He filled a large weather balloon with helium and attached a penny dispenser to it that spits out pennies one at a time. He launched the balloon hundreds of feet into the air and then a remote control device released the pennies and he ran around trying to catch them.