Desk-Chair Science

Everybody's heard of armchair scientists, but how about desk-chair scientists? That's right — you can study scientific phenomena even when you're supposed to be working.

Glare on my computer screen is much worse at 2 p.m. (bottom) than at 8:30 a.m.

Tony Flanders

Sky & Tel's recent office move was a great blessing for me because I switched from an interior cubicle to a window office. But every silver lining has its cloud. The downside of being able to see and hear the outdoors is that I have to close the blinds in the early afternoon, because the glare on my computer screen becomes intolerable when the Sun is on my side of the building.

It took me a while to realize that my computer screen was serving as an informal sky-brightness meter. The glare comes from scattered light; direct sunlight is only a problem in mid-winter, when the Sun is low. What I experience every day is the fact that the sky is many times brighter near the Sun — and particularly below the Sun — than it is on the opposite side of the sky. In fact, the change is so dramatic that it overwhelms the considerable difference between a transparent blue sky, haze, and solid clouds.

This is precisely the same effect that I had gone to great pains to measure with respect to the Moon a few months ago. And I could have done it all without budging from my office just by taking a few digital photos at different times of day!

Venetian blinds produce multiple pinhole-camera images of the Sun.

Tony Flanders

This put me in mind of an experience I had many years earlier, when I worked as a computer programmer rather than an editor. A partial solar eclipse was taking place, and I'd gone into my boss's office to offer him a view through my telescope. While I was there, I took a close look at the little line of dots where the Sun was shining through the holes in his Venetian blinds. I realized that instead of being perfect ellipses as usual, each one had a black cavity on one side. I felt simultaneously pleased to be able to show the eclipse to my boss without a telescope and foolish for never having realized before that these everyday dots are in fact pinhole-camera images of the Sun.

I wonder if really big sunspots show up on these everyday Sun images?