A bunch of scientists attempt to answer this question. Short answer: nothing good.
The Large Hadron Collider has yet to destroy the planet. But what would happen if you stuck your hand in it? In this video, a bunch of scientists attempt to answer that pressing question.
[youtube]http://www.youtube.com/watch?v=_NMqPT6oKJ8&feature=player_embedded
Simple answer: It seems like it would be the equivalent of the force of a moving aircraft carrier hitting your hand, and you would die. Actual scientific answer: no one knows.
Via Buzzfeed.