Perigee to the max!

I walked out of my biochemistry midterm half an hour ago (on Saturday no less!), thinking about stuff like gluconeogenesis and NADH. The sun had set about an hour before, so it was dark- there’s no twilight here. As I walked past the philosophy building, a cloud moved and the moon appeared. It was the biggest, whitest, brightest full moon I’ve ever seen. It lit up the whole sky, like God or Clay’s possum light. Someone with a good camera better be documenting this! It’s still there!

Then I called Travis because I had to tell him how awesome it was, and he told me that the moon is the closest it’s been for the past 18 years. Clearly I need to brush up on my knowledge of moon lore!

Also, this is my sister’s last weekend at home before she goes to Thailand. She just had to one-up me and travel even further away from home. Just kidding Melmel! All the best as you travel where no one in our family has traveled before :)

Tomorrow, visa run to Togo! Better learn some French overnight. Anyone want to tell me some key phrases? Like “No, I know the price” or “I’m married.”

So that’s what’s going on in Ghana.


4 responses to “Perigee to the max!

  1. Why is there no twilight?

  2. Two reasons:
    1. In equatorial regions the sun passes directly overhead during the day, and sets nearly perpendicular to the horizon. Compare this to the higher latitudes where the sun skirts the edge of the sky at sets at a very oblique angle to the horizon. Given that the sun travels at the same rate in both regions, it will spend a longer amount of time near the horizon–near enough that light can still be seen–in the polar regions. This is the dominant reason.
    2. Diffraction. When the sun is at more of an angle, the light must travel through a larger section of atmosphere. On its path through the atmosphere, light is slightly diffracted. The longer of a path it takes, the more diffraction. This diffraction allows the light to “bend” around the curvature of the earth so that even though the sun is below the horizon, the light still reaches you. Longer path=more diffraction=more light after sunset. If you were out in space, the light would disappear as soon as the sun went behind the earth; there would be no twilight at all.

  3. Thanks for the info!

  4. hahaha “God or Clay’s possum light”. thanks, Alan-lan!! consider yourself one-upped in terms of distance and nothing else.

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