Fried fish: Lightning cooks the crappies
DRAWING BY DEBORAH DERR McCLINTOCK
Q. When lightning strikes a body of water, is it instant fish-fry down below? How big is the kill zone? –Mrs. Paul
A. In a storm, it's no different for fish than for human swimmers who foolishly hang around. Water is a pretty good electrical conductor (no radios near the bath, please).
Lightning is high in voltage (100 million to a billion volts) and in current, but the kill-charge dissipates fast beneath the surface away from the strike point. "So fish do get killed, but probably not more than 30 yards away in fresh water, 10 yards in salt water, though good information is scarce," says University of Florida engineer Martin Uman, author of All About Lightning.
Another thing helping the fish is that they tend to hang out well below the surface, especially at night.
"In my own experience, I have only heard of one case–goldfish in a pond being struck dead by lightning, back in the '70s," says Paul Skelton, director of the JLB Smith Institute of Ichthyology, South Africa. Scuba-diving Roger Bills– another researcher there– tells of being shocked several times in Lake Tanganyika.
"On one dive, at around 20 meters I didn't feel a thing, though I saw flashes going off all the time. During decompression was when I got shocked, worse as I neared the surface– like a cattle electric fence, not incapacitating but very unpleasant. I have no idea how far off the lightning was, but I never saw any dead fish."
Q. Who hasn't complained of being forgetful from time to time? Have you ever met someone with too good a memory? –I. Savant
A. The Russian reporter Shereshevskii (known as S. in psychological circles) was once criticized for not taking notes at a staff meeting– until he proved to his boss he could play it all back verbatim from memory.
S. was also able to recall long lists of unrelated words. When each word was presented to him, report Camille Wortman et al in Psychology, he would form a concrete image of it, then place it mentally in a location along Gorky Street in Moscow. To recall the list, he would take a "mental walk" and as he passed familiar locations, the associated words would pop into mind.
The psychologist Aleksandr Luria who studied S. said the mnemonist could recall up to 50 words presented one after another, and could still reel them off 15 years later.
But S.'s "perfect" memory had its downside. Much of what he had seen, read, or heard– pleasant or unpleasant, trivial or important, from childhood to old age– stuck in his thoughts, shifting, piling up. Often, unable to see the forest for the trees, he felt confused and frustrated.
"The mere thought of such total recall is enough to make most of us content to have an ordinary memory," says Wortman, "where we remember most of what we want to or need, and let the rest slip unobtrusively away."
Q. Do left-handed target shooters need special guns? –A. Oakley
A. Many weapons can be fired effectively with either hand, including most revolvers, self-loading rifles and pistols, and shotguns, says George Washington University forensic scientist Walter F. Rowe. At most, the left-handed target shooter might have special grips fitted.
Other weapons, such as bolt-action military rifles, are generally designed for right-handers. Lefties learn to adapt– see Barry Pepper's sharpshooter in Saving Private Ryan– or have these weapons modified.
An overlooked problem for righties as well as lefties is "cross-dominance"– e.g., right-handed but left-eyed. To test dominance, aim a finger at an object, both eyes open. Then close one eye at a time. The eye for which the aim stays true is your dominant eye. Cross-dominant handgun shooters can simply tilt the head to accommodate, says gun expert Mark Duncan. Rifle and shotgun shooters sometimes change sides. Or sighting with dominant eye closed may work to some degree, but there are plenty of focusing pitfalls.
Q. How is sleep like love and happiness? –B. Cerf
A. If pursued too ardently, sleep too will elude you, says psychologist Wilse Webb. One experimenter invited volunteers to spend two consecutive nights in a sleep lab, and on the second night offered them $10 for every minute they fell asleep faster than the night before.
Send Strange questions to brothers Bill and Rich at firstname.lastname@example.org.