What's that? A backyard surprise from heaven

DRAWING BY DEBORAH DERR McCLINTOCK

 Q. Which of the following might you conceivably discover in your backyard one morning? a) a meteor b) a meteorite c) a meteoroid d) a fireball e) an asteroid –J. Glenn

A. If (e) landed there, you probably wouldn't find it or anything else, as an asteroid–large rocky body orbiting the sun, up to maybe 1000 km in diameter–hitting Earth could spell doom for us all, says University of Hawaii astronomer Karen Meech. You wouldn't find a meteor there either because, by definition, a meteor is the fiery streak you might see in the sky as the friction of the atmosphere causes a meteoroid (usually pea-sized or smaller) to vaporize in a heavenly light show.

You might, however, find some rocky fragment of a meteoroid that makes it all the way through the atmosphere to the ground, becoming a "meteorite." So the answer is (b). "Every now and then, a very large meteoroid triggers a meteor so bright it can be seen during the day, called a fireball."

Q. Why do people do crazy things when the moon is full, catch colds after getting wet and chilled, feel arthritis pains when the weather changes, become as kids hyperkinetic from eating lots of sugar, become as married couples more likely to conceive a child after adopting one? Clue: Amazingly, the same answer applies in all of these cases and many more. –J. Dixon

A. They don't, they don't, they don't, they don't, they don't! Why so many people believe they do has to do with "illusory correlation," says David G. Myers in Psychology (7TH ed.). In the moon case, imagine the four possible situations and outcomes: 1. Full moon, something weird happens; 2. Full moon, nothing happens; 3. No full moon, something weird happens; 4. No full moon, nothing happens.

Clearly, when we believe a relationship exists between two things, we are more likely to notice and recall their occurrence together, says Myers. So the 1's above will be duly noted, while the 2's, 3's, and 4's– no matter how much more frequent– will be ignored. It's hard to imagine a weird evening and then someone exclaiming, "Hey, there's no full moon tonight. Maybe that moon stuff is baloney."

No great harm done with the "lunar effect," but confusion over cause and effect can lead to social and medical mythologies, as in the other cases.

Q. Even if you're just a weekend duffer, you no doubt live in the hope of someday putting together a really good round of golf. Could a computer tell you your chances? –A. Palmer

A. A computer armed with your scorecards and applying probability theory may give you at least a crude estimate, says Theodore Jorgensen in "The Physics of Golf." He tallied the scores of one golfer over half a season and found on a particular par-four hole that the player had shot 2 birdies, 3 pars, 14 bogies, 2 double bogies, and 1 triple bogie in 22 rounds. So his chances of getting par for this hole were 3 divided by 22, or .136.

Using the probabilities determined for each of the various scores on each of the holes, Jorgensen was able to calculate the likelihood of this golfer having any particular score on a round of golf. For instance, he could break 80 by shooting par four on 10 holes, bogies on 5 holes, and double bogies on 3 holes. Myriad other combos were possible.

Running these all through a computer, Jorgensen found that this particular golfer had about a 3-in-100,000 chance of breaking 80. In other words, if he played a round every Saturday afternoon for 2,000 years, he could expect to break 80 three times!

Send Strange questions to brothers Bill and Rich at strangetrue@compuserve.com.

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