What happens when people spend too much time in a dark room

Every once in a while I stumble upon a medical discovery that renews my hope that one day, we might through our astounding ingenuity finally conquer all human disease and suffering. Indeed, today I feel warmed by the promise of a field of medicine that can teach us that, in fact, the penis assumes a boomerang shape during coitus. Here is the study, in PDF format. May you bask in the radiance of its intellectual triumph.

(Click on the "Begin manual download" button in the center of the screen if the study does not appear.)