Could be worse.
See, there's this thing called the coefficient of friction- that is, a measure of how hard it is to slide one material over another. You need to know this to be able to tell how hard you need to push something to start it moving.

My old physics textbook had a problem in it, in which they asked us to determine how much heat was generated by the friction in getting your face slapped. They gave a coefficient of friction for skin against skin in that problem.

I took that number, made a few size and pressure assumptions, and calculated how much heat was generated during a typical wank, assuming no lube.

It was days before anyone would look me in the eye.
( The Resident Loon Not a demographic. Do not measure., Thu 16 Apr 2009, 19:44, Reply)