Strange Science

You've heard the stories: Alligators live in city sewers. Pets wind up in microwave ovens. Pickles glow.

These urban legends can't be true. Or can they?

Enter Ursula Gibson '76, Thayer School of Engineering's resident debunker. She welcomes any opportunity to apply the scientific method to test the plausibility of such stories. Gibson, who teaches an introductory engineering course called "Everyday Technology," enjoys bringing her scientific do-it-yourself approach to ordinary problems. "I don't want students to be terrified of technology," says Gibson. "I want future lawyers and bankers to know they can take apart a broken VCR, figure out what's wrong and maybe even fix it with something as simple as superglue."

Gibson applies the same practical approach to her investigations of urban legends. But that often requires more than superglue, as these examples from Gibson's lab experiments attest.

The Case of the Glowing Pickle

The Legend: An ordinary pickle will glow if plugged into an electrical outlet.

Ursula Explains: "I tried this one at home with a baby gherkin. I cut the end off an extension cord, removed the insulation from the ends and stuck the wires into the pickle. With great caution, I inserted the plug into the outlet. I was disappointed that the pickle seemed not to be responding. I thought that perhaps the light from the pickle was too dim to see, so leaving the pickle in the 'on' position, I turned off the kitchen light. I heard some spluttering noises emerging from the pickle. I dashed back and was pleased no end to see some flashes of light from the electrified pickle. The light also revealed dark curls of acrid smoke, looping gently toward the smoke detector.

"If you're looking for an inexpensive, reliable and lownoise night-light, I recommend a four-watt bulb, not a one-ounce pickle."

The Death of Little Mikey

The Legend: Remember the super-effervescent candy called Pop Rocks? It has been purported that little Mikey, the cute tyke from the old Life cereal TV commercials, swallowed a handful of Pop Rocks, drank some soda and then died when his stomach exploded from all the fizz.

Ursula Explains: "The Little Mikey story reminds me of an unwitting experiment I witnessed in graduate school. We grad students were playing with liquid nitrogen, the stuff that is used to freeze warts. One of us discovered that you could put the stuff in your mouth. As long as you kept the liquid nitrogen moving, it didn't burn you, and you could exhale the vapor so that a cloud of smoke came out of your mouth. One of my colleagues was demonstrating this when he accidentally swallowed some of the liquid. There was a moment of horrified silence, and thence came not an explosion, but the most remarkably protracted belch that I have ever heard. Mother Nature clearly knows just what to do with excess gas in the stomach.

"Which brings me to Pop Rocks. I got some on sale and experimented with them. When put in water, they released much less gas than a typical carbonated beverage. Even combined with soda, Pop Rocks would be an unlikely cause of a stomach explosion. There have been cases where a stomach was ruptured by a combination of baking soda and vinegar, according to the medical literature. That's plausible, since those are the ingredients of erupting homemade volcanoes you see at school science fairs.

"And for the record, actor John Gilchrist, the original Mikey, is alive and well."

Exploding Underwear

The Legend: Rumor has it that during the 1960s a woman wore an inflatable bra aboard a jet airplane. When the plane gained altitude, the bra exploded.

Ursula Explains: "At takeoff, the air pressure inside an inflated bra would be equal to the air pressure in the cabin. But as the plane gains altitude, the forces outside and inside the bra become unbalanced. While expanding to compensate for the lower external pressure, the inflatable undergarment could rupture. An analogous episode would be that of the private pilot who heard explosions somewhere behind him during a high-altitude flight. He landed, checked his engine, but found nothing wrong. After this sequence repeated itself on his next flight, the pilot finally came upon burst bags of potato chips in his cabin."

The Poodle in the Microwave

The Legend: A woman tried to dry her poodle by placing it in a microwave oven. A furry explosion ensued. Ursula Explains: "An explosion would require a fairly significant buildup of pressure inside the poodle, presumably by conversion of liquid to gas. That would take quite a long time—think of boiling a gallon of water in your microwave but might be possible. I would prefer to believe that no one would attempt it. Certainly the poor animal would let you know it was unhappy long before it cooked or exploded."

Radio Reception in Dental Fillings

The Legend: Metal fillings in your teeth can receive radio signals.

Ursula Explains: "The answer to this one seems to depend on your definition of reception. If you mean that someone other than the filling owner heard the signal, the claim has never been documented as true. The physics of the situation would require the person to have a small radio frequency generator in the mouth, not to mention a structure that was capable of oscillating at audio frequencies. If you mean that the filling owner could hear the signal, the claim is probably false, but the answer can't readily be proven, so it's probably not worth pursuing. If, however, you mean that the energy in the radio waves was perceptibly transferred to the filling owner, the claim is probably true. If the filling consisted of materials that could absorb some of the energy of the radio waves, the filling could heat up, similar to the heating that a microwave does. There isn't much energy in radio waves, so you'd probably have to be close to the transmitter to get that effect."

With practical know-how and a dose of humor, engineering professor Ursula Gibson '76 pulls apart the tallest of tales.

Can pickles really glow? Gibson doesn't sit and wonder—she investigates.

SHIRLEY LIN is this magazine's Whitney Campbell intern.