Monday, March 20, 2006

Happy Spring

Spring will officially begin at 12:26 pm CST as the Vernal Equinox arrives.

There is an old saying: "If the wind is northeast or north at noon of the vernal equinox, there will be no fine weather before midsummer. If the wind is westerly or southwesterly, there will be fine weather until midsummer. "

The word "Equinox" means "equal night." Because the sun is positioned above the equator, day and night are about equal in length all over the world during the equinoxes. The daylight length is virtually the same everywhere today: 12 hours and 8 minutes.

There are not exactly 12 hours of daylight and 12 hours of darkness on the spring and fall equinoxes. On the equinoxes, the very center of the Sun sets just 12 hours after it rose. But the day actually begins when the upper edge of the Sun reaches the horizon, and it doesn't end until the entire Sun has set. The Sun is actually visible when it is below the horizon, as Earth's atmosphere refracts the Sun's rays and bends them in an arc over the horizon.

No comments: