Diving Thoughts

This morning we had a partial solar eclipse in Hong Kong. It was predicted to happen between 08:15 and 10:46, with the maximum eclipse at 09:26.

Obviously staring up at the sun, even through sunglasses, is not a sensible thing to do so I needed an alternative.  Ten years ago I was in Munich for a total eclipse and I was far better prepared, with some of those eclipse goggles to allow me to watch it. Today I decided to try out a couple of alternatives. Borrowing from the image on the right from the Hong Kong Observatory, I stuck a pin through  a sheet of paper three times (to see what difference larger or smaller holes made).  I also took down a pair of binoculars, not to look directly at the sun, but to project on to the cardboard.

So first of all I tried with my ridiculously simple pin-hole device, secure in the knowledge that it wouldn’t work. Immediately I was quite taken aback when I saw 2 small crescents projected on to the cardboard. The third “pin”-hole was too big and was ineffective.

Flushed with the unexpected success of my very simple pin-hole device, I then tried to use a pair of binoculars to project an image of the sun on to the cardboard. This took a bit more effort aligning the binoculars with the sun and the cardboard but eventually I managed it, and was blessed with a sharp, bright crescent that was considerably larger than I’d got out of the pin-holes. In fact I got 2 images, one for each lens in the pair of binoculars, but they were large enough that I could only fit one of them on my cardboard box at a time. A telescope on a tripod would have made life a lot easier, as it was quite difficult to keep the binoculars aligned, and I couldn’t hold them steady enough. But despite that, I would still count the morning as a success and I was really pleased to have been able to see the eclipse in such a simple way.