The Colour of White

The results of activity in the human brain often show it to be a very fallible organ - just look at the 'theory of intelligent design', for example, or reality television, personalised car number plates, the Health & Safety Executive. Someone somewhere, outwardly sensible and rational, we hope, must have thought these a good idea. And they're not.

However what the brain is good at doing is the bits it doesn't usually expect us to think about, like breathing or what the colour of white light is. In today's image a warm coloured tungsten table lamp is sat next to the cold light from a window facing north. The contrast is very obvious, to the camera, at least, but not necessarily to the innocent bystander. I notice it because I'm trained to - I have to correct these differences using coloured filters (blue or orange in various strengths) when I'm matching lights sources for television cameras. But, generally, we don't notice these things as we go about our daily lives. We might think it strange that the light from a television set seen looking in through a window at night looks blue but doesn't when we sit in front of it. Mostly we don't notice. The brain and its mate, the eye, sort it out, leaving us to get on with our lives.

Incidentally, I wouldn't like people to think that the brain is perfect when it comes to colour. If it was, you would never see anyone wearing a combination of red and purple. But you do.