Imagine you can see 160 years of history, all on one screen. You can zoom and pan, you can look at a particular day, you can even do a search. And when you do, the results come up not as a list, but as a heat map that shows where in history that topic appears, and how often.
D. Shahaf, C. Guestrin, and E. Horvitz. Proceedings of the 18th ACM SIGKDD international conference on Knowledge discovery and data mining
, page 1122--1130. New York, NY, USA, ACM, (2012)