From Alan C
Your item on ultraviolet vision (22 February, p 7) reminded me of the time I discovered I could see a little way into the ultraviolet.
In my first year at university, we were measuring the wavelengths of the spectral lines in the potassium vapour spectrum. I was taking much longer than the rest of the group, so the tutor came over to see why. He looked at my results and exclaimed, “You can’t see those!” So I lined up the spectroscope on three of the lines while he checked the textbook. “You’re right,” he admitted. “You’re seeing ultraviolet.”
In a long and very varied career since then, I have had many opportunities to check, and I can definitely see a short distance into the ultraviolet. It would be interesting to know if any other New Scientist readers can do this. I have met only two other people who have this ability.
Congleton, Cheshire, UK
. Larman
