According to wikipedia, authors use footnotes "to escape the limitations imposed on the word count of various academic and legal texts which do not take into account footnotes. Aggressive use of this strategy can lead the text to be seen as affected by what some people call "footnote disease".
I really want to go see this exhibition on at the Huntarian called the Craft of Microscopy. It's a mix of craft and technology with really beautiful photography. And its free!