"Science doesn't always go forwards. It's a bit like doing a Rubik's cube. You sometimes have to make more of a mess with a Rubik's cube before you can get it to go right. You build up this picture of what there is and you believe it to be true and you work with this picture and you refine it but sometimes you have to abandon the picture. Sometimes you discover the picture you thought you had, that everybody thought we had, actually turns out to be wrong."