From Duncan Watts' Six Degrees: The Science of a Connected Age (pp. 61-62):

Physicists, it turns out, are almost perfectly suited to invading other people's disciplines, being not only extremely clever but also generally much less fussy than most about the problems they chose to study. Physicists tend to see themselves as the lords of the academic jungle, loftily regarding their own methods as above the ken of anybody else and jealously guarding their own terrain. But their alter egos are closer to scavengers, happy to borrow ideas and techiques from anywhere if they seem like they might be useful, and delighted to stomp all over some else's problem. As irritating as this attitude can be to everybody else, the arrival of the physicists into a previously non-physics area of research often pressages a period of great discovery and excitement. Mathematicians do the same thing occasionally, but no one descends with such fury and in so great a number as a pack of hungry physicists, adrenalized by the scent of a new problem.

Duncan Watts "holds a Ph.D. in theoretical and applied mechanics and has published in leading physics and sociology journals" according to his book.