The Autumnal Equinox

photo courtesy of Spencer Greet

September 22, 2008


Today is the first day of Autumn in the Northern Hemisphere.


That means it is the day of the Autumnal Equinox, when the amount of daylight and darkness is roughly equal; that is, the suns spends nearly an equal amount of time above and below the horizon. I mentioned this in my post of September 18, but since today is the actual day of the Equinox, I decided to refresh my gradeschool-era knowledge of why this happens.



The Earth is tilted about 23.5 degrees from the vertical on its axis, which is the imaginary line that runs through the Earth from pole to pole, and around which the Earth rotates. That means that the Earth has "seasons", meaning that the weather does not remain constant, but changes over the course of a year.



During the months of June, July and August, the Northern Hemisphere is tilted toward the Sun, making it summer in that part of the world. In the Southern Hemisphere, it is winter during those months. But as the Earth continues its rotational journey around the Sun, eventually it reaches a point where the Sun is right over the equator, marking the equinox ("equal night" in Latin).



How high the sun reaches in the sky depends on the hemisphere and the latitude of your location. Near the North Pole, for example, today is the day when the sun actually dips below the equator for the first time since the Spring.



In the Southern Hemisphere, today is the day of the Vernal Equinox. Summer has just ended, and Spring is beginning. Because both hemispheres are at equinox, the weather is actually very similar at equal latitudes above and below the Equator; both hemispheres are getting the same amount of light.



To celebrate the Equinoxes (and the Solstices, as well), one of my neighbors has a bonfire that is visible from my deck. I am not sure why he does this, but it is kind of fun. There is a vaguely Pagan feel to it; equinoxes and solstices were greatly celebrated in ancient Celtic and Druidic cultures.



I plan to celebrate the Autumnal Equinox by going to the YMCA, which my family recently joined, to begin yet another workout routine. One thing I would like to achieve by exercising is to improve my balance, which has never been really good. Several years back, I dislocated my right elbow because I tripped over my purse, lost my balance, and fell on my extended right arm.


Gravity is not our friend, as we find out when we hurtle to the ground after a fall. Not only does it tug at the skin of our faces, necks and upper arms, leaving us with wattles that are the envy of the turkey community, it yanks us down with a vengeance as soon as we get a little cocky. Just try to defy gravity for a few seconds and see what happens.


Falling is one of the great dangers of getting older. As people, particularly women, age, they are subject to osteoporosis, which is a weakening of the bone mass. This weakening is why older persons are vulnerable to broken bones.



Exercise can help to improve balance and strengthen bone, a double benefit.


Plus, it may help me get rid of those award-winning wattles and get me back into those size-6 jeans that I keep hanging onto.