You'd think it has to do with the amount of deep background knowledge required to come up with useful model systems. Chemistry and biology are messy subjects.

You'd think it has to do with the amount of deep background knowledge required to come up with useful model systems. Chemistry and biology are messy subjects. Who again said that he wanted to do mathematics until the age of twenty, then physics until the age of 30, chemistry until 40, biology until 50, and the classics of the rest of his life?