Not all scientists are the quiet, serious type. Science writer Carl Zimmer offers a unique peek under the lab coat on his site Science Tattoo Emporium.

Julian, who sent Carl the above picture of his tattoo of the testosterone molecule, writes:

The tat has to do with my love of lifting heavy weights and the most important molecule for that is testosterone. People can take all the synthetic testosterones and steroid derivatives they want but nothing feels better than knowing after a heavy lift that all you used was that which your testes produced.

So much for the stereotype of the timid scientist who avoids sports or physical exertion.