Browse archives: 2007 | 2006 | 2005 | 2004 | 2003 | 2002 | 2001 | 2000 | 1999 | 1998 | 1997 | 1996 | 1995

Published on 09/22/1997 All articles from this issue

Fall is here

printer friendly version

By Howard Jarmy

Fall has come, the air has found ourselves tending to tasks suited to the season. We pull overaged veggies from the garden, ivy, prune the trees, cut down on the watering of the lawn. The furnace is about to receive more attention, too, having been quiescent the last several months. The filter needs changing, the motor oiling.

All this because the earth is speeding toward the sun at this point in its orbit. But don't worry. We will not run into the sun, will not be incinerated because we are getting too close to it. This situation has been going on for eons and everything is under control.

Toward the sun, you ask? Wouldn't it seem we should be speeding away; after all the weather is getting colder, not warmer. This viewpoint simply shows we are beholden to having grown up in the northern hemisphere. We know, once we stop to think about it, that the southern hemisphere has weather opposite to ours. We visit South America and Australia in our winter because then it is warm in those places. Cold here, warm there. And, of course, warm here, cold there.

Our favorite astronomer, Adam Baum - and yes, his parents, Mr. and Mrs. Baum, displayed a wry sense of humor when naming him - is used to explaining the situation. The earth, he says, is tilted on its axis, the northern hemisphere being tilted away from the sun during our fall and winter months and receiving its rays more or less obliquely. This transfers lesser amounts of energy to the earth's northern surfaces and, conversely, higher amounts of energy to its southern surfaces because there, the sun's rays strike almost perpendicularly. And all this happens, as Baum reminds us, as the earth is approaching the sun.

On the other hand, during our spring and summer months, the earth is speeding away from the sun. But because of the tilt of the earth on its axis, the sun's rays now strike the northern hemisphere almost perpendicularly, warming it. The rays also strike the southern hemisphere obliquely at this time, giving minimum amounts of energy to it.

Adam Baum reminds us to sit tight. "Everything is under control," he says. "Don't worry, be happy." He's a cheerful sort of fellow.

Howard Jarmy is a Los Altos resident and occasional contributor to the Town Crier.