Solstice
There has been much confusion, albeit in my mind only, about whether the solstice occurs on the 21st of the 22nd of June. I had always believed it occurred on the 21st but this morning on the radio they were saying today was the shortest day. (I expect you’ll all observe the occasion by dancing round a bonfire and drinking copious amounts of mulled wine.)
So I’ve done a little research that we can all throw in to casual conversations today.
Exact time of the solstice varies from year to year. Leap years throw it out a bit (or bring it back into line depending how you look at it).
I knew the solstice wasn’t a whole day, that there must be some exact point in time, where the sun, being directly overhead at whatever given point on the earth, would reach it’s seasonal nadir (or zenith but I’m in the southern hemisphere… and it’s all about me).
My research here, tells me that the solstice occurs at 18.06 UTC, 21 June 2007. So yes, it happens on the 21st at the prime meridien but here in Adelaide, it happened at 03.36 CST, and 04.06 EST for most other people in Australia. (Except in John Howardville, where the time is the same but the year is 1957.)
Let’s dig a little deeper though.
I think I’ve worked out (could be completely wrong here) that the solstice will coincide with solar noon at somewhere near 90°W and at the equator the sun will be at an azimuth of 73°.
The nearest geographical location to the equator (ie place you could go to without a boat) would be the south coast of Guatemala. There, at noon, or 12.06 the sun would be at an angle of 81°. But if you were to go north, to the Yucatan Peninsula in Mexico, you could get the closest to the Tropic of Cancer, where the sun would be at it’s highest point in the sky and at its most northern point for the year.
And your shadow would be at it’s smallest.
And bald spots would be at their most vulnerable.
And narrow-brimmed hats would be most effective.
