[rubidium]

To get more data, check out http://chemistry.library.nd.edu/resources/genealogy/physics/ http://genealogy.math.ndsu.nodak.edu/ <--lots of Mathematicians.

You could probably figure out a way to take those data sets and incorporate them, as they're relatively complete and well researched.

I'm glad to see you allow for multiple advisors, as that seems to show up every now and then.