We lie on the brink of change. Great storms are brewing. This is the week of equinox, when the Earth stands up straight to the sun before it begins to tilt again, northern hemisphere tipping outward.
At this moment everything hangs in balance. The hours of day and night are nearly even. There's some powerful physics at play.
I remember Oregon Coast fishermen, charter skippers and commercial trollers, standing around the bait shop scolding the weather. The worst storms and the most unpredictable catches occurred at equinoxes, they said. Nasty storm clouds would rise out of nowhere and turn the ocean black, threatening lives. Then, quick as cream in a cat's mouth, the clouds would be gone. Skies would clear. Fish would bite.
Satellite signals get scrambled this time of year. Grouped along the equator, satellites line up with the sun during equinoxes. When this happens the tremendous energy of the sun drowns out their communications. Satellite dish owners are warned to avert the eyes of their machines away from the sun at this time lest they be damaged, their sensitive electronics fried into blindness.
Equinoxes are times of special powers, our ancestors agreed. Calendars were created around them; crops were planted by them.
For the Catholic Church, the date of vernal equinox is critical. The Sunday following the first full moon after equinox is always Easter. The Council of Nicea, in 325, established March 21 as vernal equinox. But that was on the Julian calendar, which was about 18 hours per century too long. By 1852 the true equinox had slipped 10 days, actually occurring on March 11.
Pope Gregory XIII reformed the calendar to return the equinox to March 21. The day that followed October 4 in 1852 was October 15. And to keep the calendar from slipping again it was decided that leap years would be omitted in century years unless they were divisible by 400. Consequently, the year 1900 was not a leap year under the Gregorian calendar we now count our days by, but the year 2000 will be. The year 2100 will have no leap day, should the Gregorian calendar last that long.
Of course it hasn't always been this way, spring in March and autumn in September. Twelve thousand years ago, when paleolithic hunters were pursuing woolly mammoths, the seasons were reversed. And just 6,000 years ago the pyramid-building Egyptians were witnessing summer in our April and winter in our October.
The Earth wobbles as it spins. This wobble, called "precession," slowly changes the shape of our seasons. Our descendants will change the calendar again and again, like Pope Gregory, to keep the start of spring in March, or else in the year 14990 it will begin in September, where the autumnal equinox is now.
This precession of the equinoxes leaves me dizzy. The cycle of our seasons, clearly, is but one rotation among many. The Earth wobbles as it spins in its orbit around a star that circles the center of a galaxy that is itself moving at incredible speed through the depths of space. What's a person to hold on to?
It's hardly surprising, then, that the moment of equinox, halfway between light and darkness, casts such a long shadow on human history. This is the time when all of nature shuffles nervously, feeling the collective tug of all those cycles as the Earth reaches the end of one movement, pauses briefly, and starts in anew.
