marks on the ruler should be infinitely small so you can measure more precisely
idk who this is you're going to have to tell me if this is funny or not
(it's john conway, who is known for the surreal numbers, which is an extension of the reals that includes infinitesimals (number smaller than any real nonzero number) and infinities.)
Oh, I thought this was gonna be like the king of Denmark or something and the joke was that his face was finely lined.