.by Anura Guruge
>> Spring (Vernal) Equinox 2013 … Feb. 5, 2013.
We are there at least per our relationship with the Sun.
It is now downhill all the way to Summer.
You would never know that in New Hampshire. We had a ton of snow today.
A diagram I did for yet another unfinished book!
Click to ENLARGE.
Click to ENLARGE. Take a minute to savor this classic by Botticelli. Primavera, the ‘Allegory of Spring’.
Past Google Doodles for the Spring Equinox.
Spring in Italy, with its Mediterranean climate, would start in March. The spring equinox in the Northern Hemisphere, when the length of the day and that of night are closest to being equal occurs around March 20 or 21. The equinoxes, is also when the sun, in a given geography, will rise as close to due east as it ever gets.
We have two equinoxes a year, six months apart. So the other one is in September, around the 22nd or 23rd.
In the Northern Hemisphere, following the spring equinox, the point where the Sun rises each day will shift to the northeast, on a daily basis, reaching the furthest point northeast on the day of the summer solstice (the distance between the two points more pronounced as you move away from the equator). Then, each day, the sun rise point will start moving back towards the east reaching the east most point come the September equinox. Following that, up until the winter solstice in December, the sun rise direction starts drifting to the southeast. After this solstice, the sun rise direction again starts moving back, slowly, towards the east ….
Our early ancestors, even when they were dwelling in caves, carefully observed the daily motions of the sun and the moon. In time they recognized and learnt the unvarying, regular patterns of when and where the Sun would rise (and set), as the seasons changed as made apparent by the changes in temperature and the growth cycles of trees and plants.
They also used various ‘uprights,’ whether it be sticks, tree trunks or stone columns, as early sun dials, to track, measure and understand how the length and angle of shadows caused by the Sun changed during the day, as well as on a daily basis – the day-to-day changes occurring per a repeating pattern, punctuated by the equinoxes and solstices. It, however, took quite a few millennia (probably between four to six) before all the physics associated with equinoxes and solstices would be accurately sorted out – finally coming to terms, around the 17th century, that the Earth revolved around the Sun, rather than the other way around, being a crucial step.