Science is fun! Especially when it is used to create a homemade cannon that looks so cool when it fires. This guy connected a self-igniting propane torch to some tubes and then coloured the flame so that it pops off green when it blasts. It looks like an alien's weapon!
The Backyard Scientist writes:
The torch is self-igniting, meaning it has an electric sparker built in. When the button is pressed halfway, the torch mixes a perfect combination of propane and air into the tube. When the button is fully pressed the torch sparks sending a flame flying through the tube. I tried to colour the flame with some boric acid, and it turned bright green.