musings on interesting ideas

A very confusing face:

The reason why is is so difficult to look at is because of the way our brains do face recognition.

When we look at a face our brains measure a (very small) number of distances such as the difference between the eyes and between each eye and the nose. In this picture their are two faces superimposed on each other. So when your brain tries to make the measurements it gets confused with which feature it is measuring from.

I find this interesting because when we recognise a face we are not looking at it in any great detail just measuring some key points. Also it is interesting because it suggests that when we come across highly unusual images we may not be seeing them with any accuracy at all.

A classic optical illusion is the rotating snakes:

This is not an animated graphic - it is a still picture.

The snakes appear to be moving because of the way our eyes view images and the rate at which the visual centres of your brain can process the information. If you focus your eyes on one spot of the image it appears to be stationary. If you look normally at the picture your eyes are continually scanning the picture, the amount of data your brain is receiving is too much for it and the snakes appear to rotate.

I find this a particularly interesting illusion because it raises the question of “how much can we trust what we think we are seeing”.

I came across these light bulbs on a business trip to the Netherlands. They were in a funky restaurant we went too. When you switch on the light by the dangling light switch the light bulb appears as if by magic. It is not really there and you can put your hand into it. I don’t thing these are actually holograms but an example of but the effect is similar.

The light bulb:

The light bulbs above the urinals: