Thursday, March 16, 2017

All things being equal


...means we get two equinoxes a year, vernal and autumnal as they are known in some circles or March and September as they are known in others. Solstices, which happen in June and December, are a subject for another day.

So everything is equal on an equinox, right? Day and night. Hours of daylight and hours of darkness. Sunrise and sunset twelve hours apart, right?

Wrong.

The equinox doesn't occur until next Monday, March 20th, but where I live the 12 hours exactly between sunrise and sunset came closest yesterday, March 15th, when the sun rose at 7:46 a.m. and set at 7:45 p.m. By today things had already slipped past the equal stage because sunrise occurred at 7:45 a.m. and sunset at 7:46 p.m. today in Canton, Georgia. So when were things equal? At midnight?

Turns out these things depend not only on the tilt of earth's axis but on the exact latitude on earth where you happen to live. So it's different for just about everybody.

I'm sorry if this bursts your bubble or upsets your apple cart. Don't blame me. I just live here.

5 comments:

Yorkshire Pudding said...

Latitude = scope for freedom of action or thought.
e.g. "Mr Brague allows his blog visitors considerable latitude in their comments."

Emma Springfield said...

Although I like winter better than a hot summer I am ready for it to be over. So I'll take whatever the rotation and orbit of the earth will give me right now.

Elephant's Child said...

We tack our season changes to the first of the month in which the equinox or solstice falls. Which I think is silly. So here in Oz we are officially in Autumn. And quite definitely aren't yet in Autumn.

Graham Edwards said...

Nothing in the celestial order is quite as set as common belief would have one think.

rhymeswithplague said...

I've been busy, busy, busy and derelict in responding, but I do appreciate all of you for continuing to read and comment!