ROANOKE TIMES

                         Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: THURSDAY, September 2, 1993                   TAG: 9309170408
SECTION: EXTRA                    PAGE: 1   EDITION: METRO 
SOURCE: Joel Achenbach
DATELINE:                                 LENGTH: Long


FOR 90%, LEFT MEANS WEAKER

Q: Why do we all agree where ``left'' and ``right'' are? Why isn't our ``left'' hand on our right side instead of being on our left side?

A: Imagine what life was like in prehistoric times, when people lived in caves or mud huts and had not yet agreed upon a universal designation for left and right. One of them would be lining up a putt and his caddy would have to say something like, ``I think this one breaks 6 inches from the side of the green with the big sand trap to the side where we drank the blood of the gazelle.''

There's a reason left is left and right is right. What's the most important instrument in your life, other than the remote control? Your two hands. And your right hand is probably your strongest. The left is weaker and less adept for 90 percent of the population. Thus the words for the weaker hand and the stronger hand have always reflected, quite bluntly, this bias.

``Left'' comes from the Old English word ``lyft,'' meaning weak and useless.

So it is that the stronger hand is called ``right,'' an unabashedly positive word.

If you are nimble-fingered you have great dexterity, from the Latin ``dexter,'' meaning right. If you are a klutz, perhaps you have ``two left feet,'' as the cliche goes, which would make you freakishly, doubly ``sinistral,'' Latin for left and not coincidentally the root of sinister.

``This looks like it's something that's deeply ingrained in the psyche,'' says David Jost, the senior lexicographer for the American Heritage Dictionary, who was surprised to see that the nasty terminology goes way back.

So far as we know there's never been anyone who actually had two left feet, or a left foot transposed to where the right should be, and vice versa. Surely that would be a story in its own right. Right?

The Mailbag:

It's summer, when the nation's journalism standards sink even lower than normal, and so we're actually going to answer a How question, then drop all the way down to a Who.

Someone asked us, How do they get fresh air into the cabin of an airplane cruising at 41,000 feet?

Our first thought was that they moved a lever on the dashboard from ``Defrost'' to ``Vent.'' Our second thought was oxygen tanks, stored under the wings like bombs. Our third thought was, they don't need fresh air, they just recirculate the old stuff over and over and try to land before we all die from oxygen deprivation.

Only the last has any truth to it: They do recirculate old air, after filtering it (the airlines will tell you this removes nasty bacteria). But that accounts for only half of the air, roughly, used in the air conditioning system. The other half comes through the engines into the cabin.

But of course! They can't roll down the window, and if they had a vent the compressed air from inside the plane would rush OUT, so the only place to take in air is in the engines, which are out there sucking air to beat the band.

Ken Waters, an engineer for Boeing, explains:

``If you think of the engine, think of it as three parts, a turbine, a compressor and a fan, all on the same shaft. We take air off certain stages of the compressor .... to get the right pressure. We then cool it through a pre-cooler, a heat exchanger inside the engine strut. Then we take that air and we run it through ducting down through the air conditioning packs.''

Now for the Who question. Michael A:, of Crofton, Md., asks, ``Who determines what time sunrise and sunset are?''

Dear Michael: The government, who else? The U.S. Naval Observatory has gone to elaborate measures to calculate the sunrise and sunset in thousands of cities. Not every newspaper or TV station or weather bureau uses these figures, but many do.

The Naval Observatory first uses Census Bureau data to find the geographical center of a city's population - which isn't the same thing as the geographical center of a city as described by official boundaries. In Washington, D.C., for example, the Naval Observatory locates this point at longitude 77 degrees, 1 minute, and latitude 38 degrees, 53 minutes, which, by our rough calculation, is a few steps from the north curb of E Street halfway between 3rd and 4th Streets S.W.

In Detroit, it's longitude 83 degrees, 5 minutes, latitude 42 degrees, 23 minutes. San Francisco is 122 degrees, 26 minutes, latitude 37 degrees, 46 minutes.

The observatory, noting that the sun is a disk and not a point, defines sunrise as the moment when the leading edge of the disk breaks the horizon at the population center. The horizon is presumed to be flat. Sunset is when the trailing edge vanishes. The time is rounded to the nearest minute.

The sun would set a couple of minutes earlier and rise a couple of minutes later if the Earth had no atmosphere. The air bends the sun's light.

We should add that, in our opinion, the moment of sunrise and sunset is something that should be determined by each individual. Our own view is that sunrise occurs at the first suggestion of luminousness in the East, far before the sun actually appears - that moment of promise, hope, challenge, resurrection.

\ Washington Post Writers Group



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