So, let's see how far I'm away from Paul Dirac coauthor-wise...
Not so far actually, thanks to Lee. Dirac's paper on the list above is a Nature article from 1952 on the question "Is there an Aether?" What about Albert Einstein then?
With 5 links to Albert Einstein! That's less than I would have guessed. With 6 links you can probably connect any two authors.
Unfortunately, the AMS database doesn't seem to contain experimentalists. Neither could I find any description of the algorithm used. It runs amazingly fast, and it makes me a little suspicious that in no query I tried did I get two paths with the same length, though that might have been coincidence.
So, have fun playing around.