I was reading Wiki's article on D. Hilbert, http://en.wikipedia.org/wiki/Hilbert_space, and couldn't help but smile at that photo of Hilbert with the funny hat. Is it for amusing those who can't make out head or tail of the Wiki article? What's the point of having black and white pictures of people in an article about their discovery? Is there something deep triggered in us when we go, "Boy! Look at that old codger with the beard. Wonder if they had woolly mammoths back then...". Some deep psychological feeling perhaps?