March 21 is the first day of spring. It's also the Vernal Equinox. "Equinox" literally means "equal night." If the Earth's axis weren't tilted, day and night would always be equal. Instead, we have long winter nights and long summer days. On the equinox, we are at the exact moment when day catches up with night and light overcomes darkness. At least in theory. I checked the SB News Press last night, and I find that the sun rises at 6:01 AM and sets at 6:12 PM on the equinox. Why are night and day not equal?
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Marc Kummel / email@example.com