ROANOKE TIMES 
                      Copyright (c) 1995, Roanoke Times

DATE: Thursday, December 21, 1995            TAG: 9512210023
SECTION: EXTRA                    PAGE: 5    EDITION: METRO 
COLUMN: Why things are
SOURCE: JOEL ACHENBACH


FLIES AREN'T NECESSARILY FREQUENT FLIERS

The lame-duck Why staff (why do they call something or someone a ``lame duck,'' anyway?) has a lot of answers to unload in these final weeks, starting with the answer to this question from Greg H. of Pleasant Hill, Calif.: ``Why is it that flies spend so much time wandering around in the air in the middle of the room?''

Dear Greg: A good corollary question is, what is a fly doing when it is clinging to the wall? Is it just being ``a fly on the wall''?

We spoke to Steve Skoda, a federal government entomologist in Lincoln, Neb., and he said that a meandering fly might be looking for a way out of the room. Or it might be looking for a mate. Or it might simply be reconnoitering the area, smelling the host of aromas. For a fly, your average kitchen is a theme park.

Fact is, though, flies sit still a lot.

``If you look at a time budget for a fly, most of its time will be spent resting someplace, either because it's digesting a meal or because it has no other stimulus to be out and about,'' Skoda said.

Fact: Flies are tremendously efficient fliers. Some species, Skoda says, can fly for upwards of 10 or even 15 miles without stopping.

Don't use all this information at once.

Chris P. of Cooper City, Fla., asks, ``Why do paper cuts hurt so damn much?''

Dear Chris: It is not the paper cut that hurts, it's your smitten finger that hurts. A paper cut on your back or leg wouldn't hurt much. But the hands and fingers are packed with pain-sensitive nerve fibers called nociceptors.

``The highest density of nerve endings is in the fingertips,'' says Pratap Khalsa, a research anesthesiologist at Yale.

Think about how crippling a hangnail can be. Think about how a splinter can essentially ruin your life. Think about the beyond-death experience of catching your finger in a car door.

(Digression: Years ago, people caught their fingers in car doors constantly. Now that doesn't happen so much. Cultural change? Our theory is, car doors are lighter, don't lurch as much, and are framed in more rubber.)

One other reason a paper cut hurts is that it's such a silly injury. You hate yourself for getting one. And because nociceptors don't transmit their signals very quickly, relative to other types of nerves (like heat-sensitive nerves), there's always that creepy delayed-reaction response, when you see the surgical slice in your flesh and have to wait for the pain to kick in.

Now, a follow-up to a question we posed awhile back on why the sun doesn't look like it's 93 million miles away.

Here's a fact we should have included: The sun doesn't look very far away because it's really, really big.

It's bigger than you think, in other words.

The sun has a diameter of 864,000 miles. To get an idea of how vast that is, consider that the Apollo astronauts, when they rocketed to the moon, traveled only about one-fourth that distance.

Our sun isn't nearly as big as some stars, though. Consider Betelgeuse. It's on Orion's shoulder. (Orion is the one that would look like a soldier with a belt and sword were it not, like all constellations, badly drawn.)

Betelgeuse manages to be one of the brightest stars in the sky even though it is 500 light-years away. (Our sun is only eight light-minutes away. A light-year is, as you know, a unit of distance, not time, and should not be confused with the term that applies to a 12-month diet, the ``lite year.'')

If Betelgeuse were in our solar system its surface would reach all the way to Jupiter. Mercury, Venus, Earth, Mars and the asteroid belt would all be inside the star. The diameter of the star actually varies a great deal. It's a red supergiant star that has become bloated, and kind of throbs, a puffy cloud-star.

Soon, using powerful telescopes, scientists will have pictures of the disk of Betelgeuse. It'll be the first star that's not just a one-dimensional point of light. About darn time. |Washington Post Writers Group

Finally, David G. of Punta Gorda, Fla.: ``Why do all animals make eye contact?''

Dear David: Actually, you're wrong, but it's an interesting thing to be wrong about (we justify a lot of our own statements this way).

Many animals are wary of eye contact and view it as explicitly threatening. You can freak out a dog by staring at it a long time.

Chimpanzees and orangutans will make eye contact with humans. But among chimpanzees, a chimp that stares for a long time may be begging food. Often when one ape stares at another it is the prelude to a ``dominance interaction,'' says Kim Bard, a psychologist at Yerkes Regional Primate Research Center of Emory University.

This reminds us of something we've never really addressed: Do animals have consciousness?

Maybe. We know that primates have, at the least, self-awareness, which is one component of consciousness. This can be tested with a mirror. A human child will realize, sometime between the age of 18 and 24 months, that the reflection in the mirror is himself or herself. For chimps, this self-awareness kicks in around 28 to 30 months.

But we doubt they ever achieve genuine narcissism.

- Washington Post Writers Group


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ILLUSTRATION: GRAPHIC:  Richard Thompson. 






























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