We have reached another equinox—the instant at which the center of the sun crosses declination, or the celestial equator. Though it was not always the case, we moderns now employ equinoxes (along with solstices) as our dividing lines between seasons. That means summer is over today…or will be at 5:19 p.m. EDT hereabouts, which—according to the almanac—is also the moment when autumn officially begins.
You often hear folks say an equinox is when days and nights are of equal length. Twelve hours of daylight, twelve hours of darkness. Sorry to disappoint, but this is just not the case. You’ll have to wait several more days for that balance to occur.
In spite of what you’ve likely been told, day and night are never the same length on an equinox anymore. There are several reasons for this imbalance. While the refraction of sunlight as it passes through the earth’s atmosphere has some effect, the main culprit which created the rift stems from the way sunrises and sunsets are currently pinpointed—along with the way we calculate an equinox.
The one-time fact is now just a quaint fantasy. The truth is, on an equinox, the days are always a bit longer than the nights. The original etymology of the word “equinox” is no longer valid.
Not that it matters in any meaningful way—seasons are just words we use to generalize our location along the great circular route of that annual journey we call a year.
Is today’s equinox day identical to last year’s or the one before that? Will next year’s equinox be the same?
Of course not. No two years, no two days, no two moments are ever exactly alike. Each and every second since time began has been unique…and therefore precious.
An hour ago I stood at the edge of the river and watched a handful of leaves being carried along on the slow current. A few weeks ago you rarely saw a leaf on the water, but each day now their number visibly increases. Three weeks hence the water’s surface will be carpeted by multicolored leaves from countless trees upstream.
There’s something satisfyingly eternal about seeing leaves float down a September stream. Observing their passage somehow welcomes me into time’s continuum.
I quite aware my own days on this earth are limited. Yet I can’t believe I’m the first man to stand on the banks of this lovely sycamore-lined stream and mark a new autumn by noting the leaves already slipping downstream. And I hope I’m not the last—that those who come after will treat this fine old river with love and respect…and will also find solace in greeting the season with a pause to watch leaves.