Wednesday, September 22, 2010

Think of It This Way

Equinox. It's about exactness, and perfect balance.

At sunset today, the setting sun will cross the horizon exactly due west. All over the earth. I won't see it here, there are clouds; but still it's true. I check with my compass whenever I have clear weather on the equinox, and access to an unobstructed horizon for sunrise or sunset, and it's always true. Due east. Due west. True everywhere.

At 8:09 PM our time, the celestial equator and the ecliptic intersect. (No, I can't visualize it, but I know it's true.) At 8:09 PM our time, the axis of the Earth is not tilted toward or away from the Sun and the circle of illumination cuts through the poles. At 8:09 PM our time, it is the moment when the Sun is positioned directly over the Earth's equator.

Today, everyone on the globe has exactly the same experience of daylight: exactly as much light as darkness. This is not an occasion of sadness. This is... wow. Something like actual magic.

1 comment:

robin andrea said...

I love this! You made it perfectly clear and absolutely magical. We saw it, and Jupiter. What an incredible night on earth.