Cherenkov effect.....

Here's a book that might make an interesting addition to a coffee table: An American Index of the Hidden and Unfamiliar. A study of spaces usually off-limits to the public, over the course of four years, Taryn Simon cajoled her way into dozens of obscure restricted sites and documented them with pictures and words. A sample can be seen here.

The picture is of a specific type of nuclear waste in a pool of heavy water. The scary thing is - I've seen this eerie blue glow in another facility I cajoled my way into many years ago. It's spooky to see that with your own eyes.