Amber Larson, Seth Auberon, Wisdom Quarterly; Almanac.com
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| Golden Buddhas, Kamphaeng Phet, Thailand (Piyawit Kampput/p_kampput/flickr.com) |
The Autumnal Equinox
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| Laughing Buddha (Eldholms) |
The word
equinox comes from the Latin words for "equal night." The fall and spring equinoxes are the only days of the year when the Sun crosses the celestial equator.
From then on the temperatures begin to drop, and the days begin to get shorter than the nights (i.e.,
hours of daylight decline).
Question: Why aren't there exactly 12 hours of daylight and 12 hours of darkness on the fall equinox?
Answer: On the equinoxes, the very center of the Sun sets just 12 hours after it rises. But the day begins when the upper edge of the Sun reaches the horizon (which happens a bit before the center rises), and it doesn't end until the entire Sun has set. Not only that, but the Sun is actually visible when it is below the horizon.
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| "Changing Aspens" in Snowmass, Colorado (Randall Day/almanac.com) |
How? Earth's atmosphere refracts the Sun's rays and bends them in an arc over the horizon. According to astronomer George Greenstein, "If the Sun were to shrink to a starlike point and we lived in a world without air, the spring and fall equinoxes would truly have 'equal nights.'"
Question: The autumn leaves seems to be hanging on longer than usual in my neck of the woods. Is this an indication of winter weather to come?
Answer: There's an old weather proverb that states, "If autumn leaves are slow to fall, prepare for a cold winter." Or perhaps you just haven't had the kind of wind or rain needed to shake the leaves loose from their branches. But look on the bright side -- beautiful autumn foliage for a little bit longer!
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