Indeed. So the technical answer to "what happens if you stick your head in a particle accelerator" is "nothing, since without a vacuum particles can't be accel

Indeed. So the technical answer to "what happens if you stick your head in a particle accelerator" is "nothing, since without a vacuum particles can't be accelerated to high speeds" -- the question answered by the article is "what happens if you stick your head in a beam originating from a particle accelerator".