STRANGE BUT TRUE- Big shock: Elephant took 6,600 volts

DRAWING BY DEBORAH DERR McCLINTOCK

Q. What was probably the biggest animal ever to undergo capital punishment?–G. Gilmore

A. In 1903, an elephant named Topsy killed her trainer after he fed her a lit cigarette. Most circus elephants at the time were forgiven a killing or two, so long as it wasn't a customer, but this was Topsy's third, says Sara Gruen in her book Water for Elephants.

Topsy's owners at Coney Island's Luna Park decided to turn the execution into a public spectacle, but the announcement that they were going to hang her met with an uproar. They instead contacted Thomas Edison, who for years had been "proving" the dangers of rival George Westinghouse's alternating current by publicly electrocuting stray dogs and cats, along with the occasional horse or cow. Edison accepted the challenge.

"Because the electric chair had replaced the gallows as New York's official method of execution, the protests stopped." Edison brought in "a movie camera, had Topsy strapped into copper-lined sandals and shot 6,600 volts through her in front of 1,500 spectators, killing her in about 10 seconds." Convinced that his feat discredited alternating current, he went on to show the film to audiences across the country.

Q. A world-famous newspaper editorially attacked a professor for proposing that a rocket could propel itself by pushing against empty space– a vacuum– and still receive a push back in return. "That is absurd," said the paper sarcastically. "Of course, Professor Goddard with his 'chair' in Clark College and with the support of the Smithsonian Institution ... only seems to lack the knowledge ladled out daily in high schools." What was the significance of it all?–E. John

A. The real vacuum was in the knowledge of the editorialist attacking the professor for proposing that liquid-fueled rockets could be used to travel in space, says UVA's Louis Bloomfield in How Things Work: Physics of Everyday Life.

This was January 13, 1920, and the New York Times writer was only mouthing a common misconception that a rocket needs something external to "push against" in order to accelerate and gain speed. "Of course, a rocket can't really push itself forward, any more than you can lift yourself up by your boots," says Bloomfield. Rather, it obtains a forward force, a thrust force, by pushing against its own limited store of fuel. The pair of equal but opposite forces are action and reaction– the rocket pushes its exhaust backward, and the exhaust pushes the rocket forward. Professor Goddard knew all this, but it took the larger culture a good while to catch up with him.

Q. Why would anyone be interested in quantifying traffic flows in drunken crowds?–B. Hill

A. To help minimize the congestion and fights that often break out, speeding revellers home faster and safer, says Linda Geddes in New Scientist magazine. When University of Cardiff, United Kingdom, researchers monitored Friday and Saturday late night crowds, they discovered high numbers to be staggeringly drunk. This broke down "laminar flow"– where people in a crowd line up behind others going in the same direction– and thus slowed movement by about 9 percent when a fifth of people were drunk and 38 percent when the whole crowd was, exacerbating impatience, petulance, problems.

The research team is now examining how moving street furniture or increasing pedestrianization in other ways might ease congestion around nightspots. Its crowd model can help pre-test how opening a new bar or fast-food outlet might affect a crowded city center.

Q. Out of flashlight batteries? Then go get a lemon from the fridge and do what?–L. Bug

A. Insert a galvanized (zinc) nail and a copper penny, being careful they don't touch inside, then string wires from these electrodes to hook up a small bulb, and watch for it to light. Linking several lemons in series may be necessary to get enough "juice" flowing, which works due to the chemical reaction between the zinc and the fruit acid.

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Send strange questions to brothers Bill and Rich at [email protected].

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