Astronomy

What happens at the Vernal Equinox



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What Happens at the Vernal Equinox


The word “equinox” comes from the Latin for equal night.  It might just as accurately have been named “equidies” (equal day), for at the time of an equinox the periods of sunlight and darkness in a single day are of nearly equal length (exactly equal length on the equator).  This occurs because of the earth’s tilt on it’s axis as it orbits the sun, which is why we have seasons.


When the earth’s orbit brings the sun’s equator directly above the earth’s equator, an equinox occurs.  There are two: vernal (which begins spring on March 19, 20, or 21) and autumnal (which begins fall and falls on September 22 or 23).  “Ver” and “autumn” are again from the Latin.  There are two other pivotal points in the earth’s orbit: the solstices, which begin summer and winter.  The orbit is elliptical in shape, and one could say the solstices occur at each end and the equinoxes at the two points in the middle.


From a practical point of view, what happens at the vernal equinox is the days – periods of sunlight – start getting longer than the nights if you live in the northern hemisphere.  (All of this is reversed in the southern hemisphere where spring begins in September.)  This is why the plants bud out and eventually bloom, and life in general becomes more cheerful.  Many of our present day customs to celebrate this time of year, e.g., painting eggs with bright colors, go back far into antiquity and were not associated with any of today’s organized religions unless you count nature worship.


Equinoxes can occasion another phenomenon: storms.  The sun moves south to north or vice versa faster than at any other time of year (2.5 degrees of arc or more in a week).  This rapid change in the sun’s position produces large variations in the patterns of warm and cold air masses and viola: violent storms can result.  Sailors have long known to beware the “equinoctial gales”.


Understandably, ancient people paid close attention to the sun’s position relative to the earth.  When the winter solstice occurred they knew they wouldn’t be doomed to eternal winter (though winter was just beginning, the days started getting longer again).  When the vernal equinox happened, this was a guarantee that life would reawaken and be renewed for another growing season.  Animals would bear young.  Plants would bear fruit.  And the world would – at least for a little while – be filled with pretty brightly colored blooms.


Small wonder that they saw god or the gods in these occurrences, and that virtually every culture on earth had (and has) some sort of holiday or celebration that falls on or originated from the vernal equinox: rites of spring.  Not all of the ancient customs were picturesque.  Some involved sacrificing animals or even people as symbolism of the cycle of death and renewal.  Civilization gradually banished these barbaric practices, but remnants of them can still be seen in various cultures (Shirley Jackson’s classic short story The Lottery is a good example).  And importantly, most all of these rituals originally had hope for continued life as their cornerstone.




Present day holidays surrounding the vernal equinox are important examples of what happens at that time of year.  In Japan they celebrate Shunbun no hi on that day.  It is a national holiday and an occasion for visiting the graves of relatives and having family reunions.  Many older cultures started their new year with the vernal equinox: ancient Rome for one, and Persia for another.  Present day Persia (Iran) still celebrates the New Year’s Festival of Nowruz starting on that day, as do at least a half dozen other countries.  In Egypt, Sham El Nessim was an ancient equinox holiday that can be traced back to 2700 B.C.E. and is still celebrated today, though at some point Christian influence moved it to Easter Monday.


Of course, Judaism and Christianity both still make use of the vernal equinox in fixing the date of one of their principal holidays.  The Jewish Passover usually falls on the first full moon after the equinox but sometimes on the second.  Though the eastern and western Christian churches use different calendars and therefore arrive at different dates, both fix Easter as the first Sunday after the first full moon after the vernal equinox.


Neopagans such as the Wiccans observe the equinox as “Ostara”, one of their sabbats.  Mothers Day is observed on that day in many Arab countries.  World Storytelling Day is celebrated internationally on the March equinox in the northern hemisphere and of course the September equinox in the southern.  The March date is also World Citizen Day.  And, somewhat humorously, in Annapolis, Maryland, home of the U.S. Navel Academy, they celebrate The Burning of the Socks on that day.  Apparently, true sailors only wear socks in winter, so they burn them on the spring equinox and don’t wear them again until the fall one.


With all of our marvelous technology, we often lose sight of the natural world around us.  Short of grumbling over inclement weather or enjoying hiking and camping, we tend to largely ignore the nature that our ancient ancestors elevated to the status of deity.  The Egyptian Sphinx, once excavated, showed that the huge statue (carved from living stone) and accompanying structures were oriented to the sun’s rays on the vernal equinox.  On the island of Great Britain, an ancient people we know very little about built Stonehenge, an impressive stone monument still not completely understood.  But one stone clearly marks the spot of sunrise on the vernal equinox.  Experts still can’t agree if it was merely an observatory or if it had religious significance.


In Central and South America, the Mayas, Aztecs, and doubtless many other groups built structures that clearly show an orientation to the equinox and other movements of the sun.  It is comforting and wondrous to realize as we hunt Easter eggs or visit the graves of our ancestors or celebrate a new year harking back to an ancient calendar, that we are in a way communing with the oldest of civilized cultures.  We are doing in our own way something people seem to have always done.

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