Summer kicks into high gear in the northern hemisphere today -- it's the day after the summer solstice, and the first full day of the new season.
Most of us know this because we saw it on a calendar, or heard it on a TV weather report. But in this modern age, few of us understand the astronomical significance of the summer solstice. The Sun appears farthest north for the entire year on that date. It rises well north of due east, and sets well north of due west. And it indicates that the days will soon start getting shorter.
But not so long ago, just about everyone followed the changing seasons by watching the Sun. Ancient societies built observatories to track the motions of the Sun. Some were small rooms with windows aligned to important sunrise or sunset points. Others were massive structures -- from Stonehenge in England to ChichÃ©n ItzÃ¡ in Mexico.
These societies also watched the Moon and stars. The first appearance of a particular star in the morning sky might indicate that it was time to plant crops. And the stars served as the hour hands on nighttime clocks, telling monks when it was time to pray.
In some societies, this connection to the rhythms of the sky is important even today. But for most of us, the pace of modern life, and the rise of cities, where the horizon and the night sky are blotted out, have stripped away that connection. The stars have become mere decorations -- not important markers of daily life.
Script by Damond Benningfield, Copyright 2003, 2008
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