It's wonderful how amateur science experiments are recorded on video these days, so we all can enjoy the mayhem when things go wrong. This video is a compilation of science experiments that did not go exactly as planned from Fail Army. The one that made me laugh the hardest is at 4:20, and did not involve a failed experiment, just a failed experimenter.
That said, many of these experiments worked exactly as expected, but only went wrong because of inadequate precautions. When you're dealing with potentially explosive materials, stand back and wear your safety goggles. Remember, propulsion does not automatically include aim. Protect your groin area. And don't try this at home, like many of these people did. -via Tastefully Offensive