Digg pointed out this article which states:

A committee of experts looked at all the possible excuses — biological differences in ability, hormonal influences, childrearing demands, and even differences in ambition — and found no good explanation for why women are being locked out [of science].

Umm, what about sexism? Or is that too obvious?

[Short biographies of three famous physicists after the jump]

Three biographies

Lise Meitner discovered fission and hypothesized the chain reaction. She was passed up for a Nobel in Chemistry, which was awarded to her colleague Otto Hahn.

Maria Geoppert Mayer was an voluntary (unpaid) Associate Professor of Physics at the University of Chicago when she worked out nuclear shell theory that won her a Nobel Prize.

Jocelyn Bell Burnell discovered pulsars as a graduate student. She didn’t share the Nobel Prize that her advisor Anthony Hewish won—the Nobel was split only two ways so there was room to include her.