The CERN Large Hadron Collider made the news last month when a lawsuit was filed by Walter Wagner, over his concerns that the LHC's experiments might destroy the Earth. Wagner hypothesized that the LHC's experiments could create a planet-consuming miniature black hole. Long story short: most physicists think it's quite unlikely that the LHC will kill us all...but because they're scientists, they can't categorically predict what will and will not happen. (There's a good NPR Science Friday program digging into the controversy.)

But what is the Large Hadron Collider, and what does this "biggest scientific experiment ever attempted" actually do? Physicist Brian Cox explains in a TED talk from March 2008:

See also: the very 90's-style LHC homepage. Check out the Photos section for some amazing big-machine pics.