This is an interesting article from The Scientist. Here’s an excerpt:
According to economists Benjamin Jones and Bruce Weinberg, young scientists making groundbreaking contributions to their fields are becoming an endangered breed. In a study published November 7th in the Proceedings of the National Academy of Sciences, they reported that the chances a Nobel Prize winner at the turn of the 21st century produced their winning work by the age 30 or even 40 is close to zero.
Their analysis of 525 Nobel Prize winners (182 in physics, 153 in chemistry, and 190 in medicine) between 1900 and 2008, revealed that while the mean age at which they did their Nobel-prize winning work was around 37 for the three fields in the early 20th century, they are now around 50, 46, and 45 for Physics, Chemistry, and Medicine, respectively.