The Slow-Mo Guys have been posting a lot of really cool stuff on YouTube, filming everything from slaps, to paint on speakers, to explosions.  Check out this cool video, where they got to spend an afternoon having fun shooting assault rifles in front of a high-speed camera!

So, you think that's as cool as this gets?

Check this out!  Here's an AK-47 fired underwater!  You can see all the craziness that happens when you fire a weapon in these videos.  We all just got a little smarter with this.  And the frame rate on these is 27,450fps!  Holy crap!

The Slow-Mo Guys came and helped out with this one.  Check out the channel for Smarter Every Day for more cool stuff.  I learned the word "cavitation" and about bubble bounce.