Ocular, the lens also known as the eyepiece in a refracting telescope and in a microscope.
Mass spectrometry enables the major league to sniff out athletes guilty of doping. It can also help us locate oil or design a killer perfume. Who says chemistry isn't cool?
That's one seriously big number, and technically Amedeo Avogadro didn't even come up with it. So how did the Italian chemist make such an indelible (numerical) mark on the wonderful world of chemistry?