There are all sorts of rumors and conspiracy theories about what the US military gets up to behind closed doors. We may not have solid proof that they're experimenting on aliens at Area 51, but some of the documented projects they've undertaken in the past are already stranger than fiction. The 20th century was a particularly interesting period in history, as the World Wars and the Cold War created an extra sense of urgency–and a willingness to try anything.
The more bizarre projects show up in movies all the time, from 'Men Who Stare at Goats' (2009) to 'Pineapple Express' (2008). Some of them are as ridiculous and entertaining as they're portrayed in the media, but others took a darker turn.
Click through this gallery to see some of the most outrageous experiments carried out by the US military.