A video of some nuclear reactors starting up, with sound

I was inspired by someone's username and found this video. A video much like this one was one of the things that got me into studying physics to begin with over a decade ago.

The characteristic blue glow is caused by Cherenkov radiation, which is analogous to a sonic boom, but instead of a jet breaking the sound barrier, it's charged particles moving faster than the phase velocity of light in a medium (normally water).

Pretty cool, I think.