It's one thing when a dog barks, it's another one entirely when a giant pipe full of fire does it. And it's even better in slow motion.
"The Barking Dog" is a pretty standard science experiement you might have seen in a chem class. All you do is light up a giant test tube full of nitrous oxide and sulfur dioxide, and in a split second -- bam -- a tube of flame races down and creates a light-show complete with a ear-shattering "WOOF." The guys over at periodicvideos decided to film it in slow motion though, and what you'll find is that the fire doesn't just race down; it indecisively bobs around a bit first.
The weird bobbing motion is caused by a series of shockwaves the flame shoots at the bottom of the tube as it tries to explode over and over, but there real magic is watching the ball of flame dance around in slow-mo. Just don't try mixing this with the dog flavour of barking; nobody wins at that game.