Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, April 11, 1991 TAG: 9104100240
SECTION: EXTRA PAGE: E-1 EDITION: METRO
SOURCE:
DATELINE: LENGTH: Medium
A. Because lightning didn't strike the kite.
Had it done so, "then it's bye-bye," says Martin Uman, professor of electrical engineering at the University of Florida and author of "All About Lightning." (Someday we will do away with these prolonged identifications and simply stick with "expert.")
"He was lucky he didn't get killed," Uman says. "He didn't know quite what he was doing."
Thank you, thank you, Mr. Uman. For years, since we were wee babes, we had been bothered by the Franklin experiment, because it seemed about as wise as sticking a knife in a wall socket, or pulling on a mule's tail, or dangling younger brother over the edge of a balcony.
Franklin himself never described the kite experiment. The secondhand account of Joseph Priestly states that Franklin flew a kite with string that could conduct electricity. At the bottom of the string was a key. Franklin did not touch either the string or the key, but was instead linked by a short piece of silk thread that didn't conduct electricity.
The payoff came when a sizeable spark jumped from the key to Franklin's knuckle. Lightning did not cause the spark. What did? Energy. Put it that way. There is always a flow of electrons between the sky and the ground, and it's magnified during a thunderstorm. This doesn't always result in the massive surge we call lightning; usually, we can't see it. Franklin's kite string, however, provided a channel for that energy flow, but it was still a relatively modest current. The year after Franklin's experiment, a Swedish physicist tried something similar with a metal rod. Lightning struck. He became a fritter.
One other thing: Is it safe to talk on the phone in a thunderstorm? Uman says no. The current can jump right out of the receiver if lightning hits the phone line. "People get killed every year. Lot of people get their eardrums blown out."
Q. Why isn't germ warfare more common?
A. The U.S. Army has spent about $370 million since 1984 designing defenses against biological weapons. Thousands of soldiers in the Persian Gulf were vaccinated against anthrax infection. But, as with most other wars in this century, the use of germs as weapons never occurred. That's despite the fact that losing armies presumably would use every weapon at their disposal, however heinous - Hitler put 12-year-old boys on the front line. Moreover, bio-weapons are easily made, requiring the level of technology found in any 10th grade science classroom, one expert told us.
No one is sure why the Iraqis fought the war without using any exotic weapons. Most likely, the Iraqi commanders felt the same way other military people have felt in the past: These are stupid weapons. They don't work.
"It's never worked very well. It's subject to the way the wind blows. The medical defenses are effective and easy to put in place," says Chuck Dasey, spokesman for the Army's biological-defense program at Fort Detrick, Md.
Matthew Meselson, professor of biochemistry at Harvard, points out that even if the wind conditions are right, an aerosol cloud of anthrax or some other disease may still prove ineffective because if the particles aren't tiny enough they'll be filtered out by the nose. And the dosage has to be high - the victim must inhale 10,000 to 100,000 spores to be infected.
The real question, though, is what kind of new evil could be dreamed up in the lab.
"We're in a brave new world of designer diseases," is the cheery word from Andrew Kimbrell, attorney for the Foundation on Economic Trends, a watchdog group that monitors genetic engineering. "The biological weapon is the ideal terrorist weapon."
Tom Clancy, the novelist, keeps close tabs on what kinds of weapons are in development, and the one he worries about the most is the one invented by the United States and promptly dropped on Hiroshima in 1945.
"Historically, humanity has been very inventive in coming up with new ways of killing people. But the scariest thing out there is still nuclear weapons," Clancy told us.
Could a nuclear weapon be smuggled into the United States by terrorists? Clancy says, "If you want to deliver a weapon in the United States, all you have to do is disguise it as cocaine."
Joel Achenbach writes for the Style section of the Washington Post.
by CNB