Haupz Blog

... still a totally disordered mix

A Makeshift Observatory for a Partial Solar Eclipse

2022-03-15 — Michael Haupt

One of the distinctly more nerdy things I've ever done was to optimise the machinery for observing a partial solar eclipse.

This was back in the Nineties. I was at a weekend workshop with some fellow students of electrical engineering and computer science, where we were preparing to be first-semester student tutors. As heavenly mechanics would have it, a partial eclipse was scheduled for that weekend, and we lacked the necessary equipment to observe it.

Being engineers, we came up with a makeshift solution. The key component was an overhead projector (you know these, don't you) the upper end of which we directed at the sun. With some fiddling, that gave us an image of the sun on the area where the foils are usually placed. We used a sheet of paper as the screen for our observations, and of course the intensity of the sun's image set that on fire instantly. OK, that didn't work.

I suggested to use a cup of plain black tea (no milk, no sugar). It had all the features that we needed: white surface, not easily inflammable, and the liquid had just the right amount of opacity to make the image clearly visible. A cup of tea was quickly obtained from the (somewhat puzzled) kitchen personnel of the place where we were staying (there was a narrow time window, so speed was required).

And it worked! We could see that sun cookie, with a piece bitten out by the passing moon, very clearly.

Sadly, I don't have any photographs of the experiment any more.

Tags: the-nerdy-bit