For the fortunate, fifty is the new thirty:

'Even for those lucky enough to get an academic appointment, the bad news seems to be that it is getting harder to establish a research program. For example, the average age for a researcher to get their first NIH grant (a virtual requirement for tenure for many biologists in the US) is now 42 years old. National Public Radio quips “50 is the new 30, if you’re a promising scientist.”

https://caseybergman.wordpress.com/2012/08/26/the-logistics-of-scientific-growth-in-the-21st-century/