Some interesting visualizations of library and document collections

I thought I'd pass along a couple of projects I ran across lately. This article is about 'dentographs' as  a way of visually representing library collections, the University of Toronto in this case.

And this one blew my mind. It's a 'universe' based on the articles in the arXiv, which is the main repository for preprints in physics. The colors of the 'galaxies' represent areas of physics, with the 'stars' location being determined by how closely-related they are to the core of the discipline, or to other disciplines. The 'star' size indicates the importance of the paper, based on citation counts. So a large green 'star' hovering near a blue galaxy is a 'high-energy phenomenology' paper that also touches on 'general relativity/quantum cosmology'. Don't ask me to explain what that means, but do take a look at this, it's very cool.