Ex Bibliotheca

The life and times of Zack Weinberg.

Wednesday, 27 October 2004

# 8:20 PM

As I write this, there is a total eclipse of the Moon outdoors. I was watching it, but it's cold out, and nothing much happens over the duration of totality; I'll go back out around 8:45 and watch it emerge.

The last time I tried to watch a lunar eclipse was in fall 1996. I was in New York, and it was overcast. We could see the moon through the clouds before the eclipse started, then it dwindled and became invisible at totality. Today, the skies are clear, and I can see the red disk of the Moon reflecting the light that bends through Earth's atmosphere. It was a little brighter on the ascending limb when I started watching, just a smidge before maximum eclipse. Of course I had to convince myself that that's the right place for it to be brighter; it doesn't seem like the trailing edge of the Moon (as it orbits) should be on top, as seen from here on Earth. Except of course it is. There are two things going on there. One is that the Moon's apparent motion across the sky is primarily due to the rotation of the Earth; the "proper" motion (as the astronomers call it) is west to east, which is why the Moon rises a little later each evening. The other factor is of course that, if you're standing looking at the Moon which has just risen in the east, its north pole is not on top, but on the left side.

Contemplating such things invariably puts me in mind of the little blurb in the corner of one of the pages of my mother's copy of The Next Whole Earth Catalog (which I read at an impressionable age); which was about ways of thinking to remind yourself that you were not living on a flat Earth. Unfortunately, that's about all I remember.