No threat: Twins don't fight for love


DRAWING BY DEBORAH DERR McCLINTOCK

Q. Identical twins are of course as genetically similar as two people can get. So answer this: If Twin A falls in love with C, wouldn't Twin B follow suit? -A. Morse

A. In surveying twins, researchers David Lykken and Auke Tellegen found only five percent agreed with the statement, "I could have fallen for my twin's fiancé (fiancée)." Half didn't even like the person.

Seems love's a little like the imprinting of ducklings, with repeated exposures to whoever happens along triggering infatuation so long as the person meets certain specs and reciprocates affection. "Nearly any opposite-sexed individual of roughly sibling-like similarity might serve as a releaser. What we do not understand is the mechanism of human sexual imprinting or infatuation."

Q. What's the "400 x 1/400 = 1" that sends umbraphiles off in pursuit of their heavenly love?

A. This lucky equation sums up the Moon being 400 times smaller than the Sun but at the same time 400 times closer to the Earth, so their discs appear exactly the same size in the sky, says New Scientist magazine. This makes total solar eclipses (TSEs) possible.

Possible, but with the path of the moon's shadow on Earth barely 100 kilometers (62 mi) wide, passing at times over sea or remote land or screened out by clouds during the crucial few seconds or minutes, TSEs are quite rare.

Mark this down on your calendar– as umbraphiles, or eclipse lovers, already know– that the next time you can expect the shadow to pass over your particular dwelling-spot is, on average, 360 years after the last time it passed by there. And if it happens to be cloudy, well, try again in 360 years. Which means the dedicated eclipse lover must be an eclipse chaser, going to where the action is.

Where? There's a TSE somewhere every year or so, such as November 23, 2003 over Antarctica. University of Arizona astronomer and umbraphile Glenn Schneider, having chased down a few dozen, told New Scientist of the majestic sweep of the lunar shadow and, finally, "the thin white glow of the Sun's corona, the solar atmosphere that can only be seen during a TSE." So if this captures your fancy, check a chart and book a flight. Or hope the 360-year wait for your hometown is just about up.

Q. Clap, clap, clap... on the ice. Is this the sound of audiences in raves over the new improved skating speeds, or a noise dreamed up in sports biomechanics laboratories? -S. Hughes

A. Lab wizards have long understood that the longer a skater's skates stay in contact with the ice, the longer in effect is the stride, giving more driving force, say Jerry Wilson and Anthony Buffa in College Physics. The new "clap skates"– invented by Dutch researchers and based on a century-old idea– have a spring-loaded hinge near the toe to allow the heel to lift off the blade, which stays on the ice longer for a better push. Then the blade slaps back up against the boot each time the foot is lifted off the ice.

Do the skates work? So well they were instrumental in new speed skating records being set at the 1998 Winter Olympics in Japan. Will they steal the show? "Probably not completely. On a long track where skaters compete against the clock, the clapping is no more than a slight annoyance.

But on a short curved track where skaters compete against each other, a surprise move to pass another skater would be well announced– clap, clap, clap– no surprise."

Q. Can you beat "boxed-in" thinking? Try this: On a sheet of paper, mark nine dots in a 3-by-3 square matrix, then connect them using only four straight lines, without retracings or picking up your pencil. -A. Nerd

A. Most people are stumped because of a mental set to stay within the "boundaries" of the square. Start with a corner dot, then draw a line through the two other dots of an edge and extend the line out beyond the matrix by the distance between two adjacent dots. Next draw a line incorporating the two diagonal dots and again extend beyond the matrix. Got the rest?

Send Strange questions to brothers Bill and Rich at .