Six degrees of Kevin Bacon is a fun diversion that tests one's trivia knowledge. It is also eminently suitable for electronic databases (link).

I propose that a similar engine be made for scholarly publications. One could learn who has published with whom and construct academic pedigrees and lineages.
It would also be useful for determining references to check on a person applying for a position or for funding. One might even use such an engine for "philosophy of science" type enterprises, which is sort of related to scientific pedigree.

There's a version of this for mathematicians [link]. But it's based on academic advisement, rather than publications (though the two are often related.)

This is entirely baked for the field of Mathematics - it's called
the Erdös number. According to the Wikipedia link, there are
511 people with an Erdös number of 1, i.e. these are the
people who co-authored a paper with Paul Erdös.