Heavy, man: Nothing new under the sun


Q. From a reader in the United Arab Emirates: "Many thousands of years have passed since Earth and its first creatures and early humankind appeared. These have died and gone and there are new births and growth of trees and plants. So, is the mass/weight of Earth increasing or not?" ­Dr. Atkins

A. Not, because the Earth is pretty much a closed system. Some interplanetary cosmic dust and rocky meteorites do enter, but light gases like helium and hydrogen escape from the top of the atmosphere for a mass-reducing effect.

But these are minuscule compared to the Earth's 6,000,000,000,000,000,000,000,000 kilograms. Yet as organisms die and are born, a vast recycling of elements occurs: Animate or inanimate, it makes little difference, says Penn State-Erie University geologist Tony Foyle.

"Calcium in my left tooth may have spent time inside a volcano in the western Pacific, or in a coral reef in a tropical sea many millions of years ago. Carbon dioxide I exhale today may, within a few thousand years, end up in the shell of a limpet (not yet born) on the rocky shores of Ireland."

What goes around, comes around, you know.

Q. In a race to the bottom, could a downhill skier get up more speed than a skydiver? ­J. Hingeley

A. Depends on the skier and the diver. Top skiers average over 60 mi/hour on a downhill run, peaking at near 90 mi/hour (145 km/hr), says Peter J. Brancazio in Sport Science: Physical Laws and Optimum Performance. That's mighty fast, a victory of right clothing, well-engineered equipment and proper stance to minimize aerodynamic drag like a cyclist or jockey. Here's where the skier's "egg position" comes in– tested in wind tunnels long ago– a deep, compact crouch with thighs and upper body parallel to the ground, elbows tucked inside the knees, hands near the chin.

But in skydiving, the participant tries at times to increase air resistance. After jumping, the diver falls faster and faster for several thousand feet until reaching terminal velocity– at 100 to 200 mph (160-320 km/hr) or even higher, says Brancazio. A head-first "nose dive" minimizes frontal area and drag; to slow, the skydiver adopts a horizontal spread-eagle posture, arms and legs extended.

Yet even the dallying skydiver at around 100 mph probably beats the downhill skier but not the speed skier, equipped with special streamlined helmet on an ultrasteep course at high altitudes to further reduce air resistance. Tucked into position and presenting barely half the air resistance area of someone standing, the speed-skier has been known to top 155 mph, beating the elusive 250 km/hr mark and outpacing many skydivers, but not those in a hurry.

Q. Out of 150,000 words in a standard college dictionary, how many would you guess you know? ­J. Brinkley

A. About 50,000 would be typical, so one out of three ain't bad. Assuming you learned most of these by high school, that figures to 3,000 a year, or eight every day!

That's your reading vocabulary, says lexicographer Michael Agnes. The number even a well-educated person commands for speaking is closer to 10,000-15,000, still a mouthful considering that the entire new King James Bible uses only 13,000 different words, and poet William Butler Yeats got by on 10,000. Shakespeare stretched this to 30,000, while introducing hundreds of new ones, such as luggage, dwindle, and primrose path.

Most of us manage on 2,000-3,000 words for everyday speech. In fact, a mere 150 make up about 50 percent of spoken English, and a hard-working 10 words get 25 percent of the action: the, of, and, to, you, have, will, be, it, I.

Q. If conscience doesn't forbid you pulling off the "Dollar Bill $windle" at a party, how stacked are the odds in your favor? Works like this: You pull out a U.S. buck with eight serial number digits, and offer even money to anybody who can guess three different digits on the bill in three tries. ­V. Iverson

A. Great sucker bet, says Harry Anderson in his Games You Can't Lose. Most people figure since eight digits out of 10 leaves just two missing digits, it should be easy enough to dodge these two on just three guesses. Wrong! They're forgetting about duplication!

Take a look at several bills. Digit duplication is the rule. In fact, assuming random serial numbers, fewer than one bill in 50 will have eight different digits. And even here, the caller has only about a 47 percent chance of hitting on all three guesses. That's not bad, but with just one duplicate (seven different digits), chances drop to about 29 percent, and get worse fast beyond that. Overall, it's a dismal 17-3 (15.4 percent) against your hapless mark.

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