The video depicts gamma radiation in Germany for the recent 100 days, updated periodically. Brighter dots indicate higher radiation.
Read more here: sendung.de/2011-07-11/radiation-is-there-and-so-is-the-data/
See here for the equivalent video of June to December 2011: vimeo.com/34656566
Music: I by Telecult Powers (templeofpei.com/telecultpowers.html)