Wednesday 21 September 2011
Official first day of autumn?
I had to mention it on the blog: today should be the autumn equinox, being the 21st of September and all, but apparently it will only be on the 23rd. In my mind, it starts on the first day of September anyway,but this year it seems that it showed up much earlier anyway. Still, it is the 21st of September today and it sure feels like autumn.
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4 comments:
Il y a une chanson de Brassens pour presque toutes les occasions.
How can the date of an equinox change? I thought that they were fixed days. How very confusing...
The equinoxes and solstices are sidereally (or more accurately, solarly) defined, and the revolution of the Earth around the sun is not an integer multiple of its rotations on itself. The year is 365.2422 days, thus these events tend to hover around 2 days on the calendar.
NB: Once again, a weird coincidence of a word verification: venusly.
Weird.
Thanks PJ for the explaination, very interesting indeed.
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