We went to Jodrell Bank near Manchester on Saturday. It was one of my early blog posts and it has been 4 years since we went. I'd never really thought about why they had chosen to paint it white. It turns out to be because black absorbs infra-red heat radiation from the Sun most effectively. That would make the metal expand and distort the very precise shape of the parabolic mirror. They claim that the shape of the 76m dish is out by only a few millimetres in the dish.
