What have you changed your mind about?

Brief essays on the nature of probability, science as faith and the role of phenotype (as opposed to a genotype) in evolution are some of the responses you will find to the web site Edge's annual question to some of the world's most prominent researchers and scientists.

The question this year is what have you changed your mind about and why?

But perhaps my favorite so far - I have not read them all - is the reality of imagination from Psychologist Alison Gopnik, who said that "[t]heories, in science or childhood, don't just tell us what's true - they tell us what's possible.... I don't think anymore that Science and Fiction are just both Good Things that complement each other. I think they are, quite literally, the same thing."