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WE ANSWERED! EXPERTS REVEAL THE SHOCKING TRUTH BEHIND THE MYSTERIES OF SCIENCE.

Why do sharks like to eat people?

Erika Acosta, 13 Compton, CA

Don't kid yourself! Believe it or not, sharks don't find us too appetizing. We're too lean. They prefer to dine on choicer, rattier meats of seals and sea lions. To survive in the vast ocean, sharks eat for long-term energy storage. So they prey on calorie-packed meats.

So what about all those shark-attack tales? Well, surfers and divers in black wet suits flapping vigorously in the water look a lot like sharks' favorite/seal meal. But after one chomp (jargon) chomp - To lose; specifically, to chew on something of which more was bitten off than one can. Probably related to gnashing of teeth.

See bagbiter.

A hand gesture commonly accompanies this. To perform it, hold the four fingers together and place the thumb against their tips. Now open and close your hand rapidly to suggest a biting action (much like what Pac-Man does in the classic video game, though this pantomime seems to predate that).
 ... ick! Sharks usually give up and swim the other way. Researchers note that sharks attack people only when we invade their territory, disturb their mating rituals, or when they go crazy after smelling blood in the water.

Consider this: In 1997, 57 unprovoked shark attacks on humans were reported worldwide; 11 of them were fatal. But every year humans kill millions of sharks for food (shark's fin is an Asian delicacy) and (some people shark cartilage prevents cancer). With most shark species threatened by extinction, it's a shame that "FISH EATS HUMAN" grabs more headlines than "HUMAN EATS FISH."

If Earth suddenly stopped spinning, would we fall off?

Melissa Harris, 11 Hollywood, FL

No, we won't. Gravity is the force that keeps our feet on the ground. But gravity has nothing to do with Earth's spinning or rotation. Gravity is a natural force of attraction, exerted by every object in the universe with mass. So even if Earth stopped rotating, gravity would still keep us grounded.

So what would happen if the Earth stopped spinning? Theoretically, if Earth called a sudden time-out and screeched to a halt, our atmosphere would still zoom at its usual rotational pace of 1,770 kilometers (1,100 miles) per hour at the equator. That force alone would tear away anything not attached to Earth's bedrock (solid rock beneath the soil) like buildings, cars, and the rest of us.

But don't worry. Remember Newton's First Law of Motion: Once something is in motion, it will keep going until some external force stops or changes it. Earth's rotational axis (spin pattern) is so stable, it would take a massive force like a smash-up with another planet-size object to stop Earth's spinning. And scientists say the chance of that happening in our lifetime (or any lifetime) is practically ZILCH!
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Copyright 1999, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

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Title Annotation:why sharks attack humans; gravity and the rotation of Earth
Publication:Science World
Article Type:Brief Article
Date:Mar 8, 1999
Words:405
Previous Article:SEARCHING FOR BLACK BEARD.(shipwreck off North Carolina coast may be Blackbeard's)
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