Need a cure for Thursday morning yuck? How about watching someone fill a water cooler bottle with a burst of flame? In slow motion?

This is a quick experiment that you can do at home. By that, I mean it is physically possible to do at home, not that it is actually a good idea to do at home. Yes, even if you do promise not to sue. All you need it some isopropyl alcohol, matches, and a big jug that you - preferably - don't need to use again. It needs to have a tight neck. Pour a very little alcohol into the bottle and either roll it or shake it until you coat the sides of the bottle with alcohol. Pour out the excess liquid. (This is very important.) Next grab a match and either tie it to a long stick or resign yourself to burnt fingers. Light the match and hold it over the neck.

What you should hear will sound approximately like, "Fwoosh - AAAAAH!" The fwoosh is the alcohol fumes in the bottle catching fire. Alcohol evaporates quickly, especially if a thin layer is spread out over a wide surface like the inside of the bottle. However, there will be a - literal - bottleneck in the evaporating alcohol's journey to get out of the jug. When the match ignites the fumes, the entire inside of the bottle will go up. The sudden heat will lead to rapid expansion of the gas and fire will shoot out the top. The "AAAAH," will be you either being startled and thinking you're going to burn your fingers, or actually outright burning them. Either way, it's cool to see in slo-mo.

Via Wonder How To.