PopSci answers the question everyone will be asking once they see The Watchmen preview and its blue-skinned nuclear superman: How worried should you be if you’re stuck inside the Large Hadron Collider when it goes off? It’d probably be as safe as a CAT scan, but:
If engineers were to lose control of the beam, however, watch out. The beam is only one millimeter wide, yet it contains 320 trillion protons moving just shy of the speed of light.
What would that do? Make a hole in you very quickly, and saturate the rest of you with all kinds of exciting new radioactive particles.