Why doesn’t the Earth move when we move our eyes ?

This is another of those questions to which the 1st response is often ‘Why should it?’ But think about it – when something moves in the external world, its image moves across the retina, the ‘screen’ at the back of the eye. If something is stationary in the external world and we move our eyes past it, its image will move across the retina in the same way. – How do we tell the difference ?

Read More

Local News