Yet, despite its accomplishments and glamour, the world of particle physics is so abstract that few understand its implications, meaning, or use. Unlike a NASA probe sent to Mars, CERN’s research doesn’t produce stunning, tangible images. Instead, the study of particle physics is best described by chalkboard equations and squiggly lines called Feynman diagrams. Aage Bohr, the Nobel laureate whose father Niels invented the Bohr model of the atom, and his colleague Ole Ulfbeck have even gone as far as to deny the physical existence of subatomic particles as anything more than mathematical models.

Which returns us to our original question: What happens when a beam of subatomic particles traveling at nearly the speed of light meets the flesh of the human body? Perhaps because the realms of particle physics and biology are conceptually so far removed, it’s not only laypeople who lack the intuition to answer this question, but also some professional physicists. In a 2010 YouTube interview with members of the physics and astronomy faculty at the University of Nottingham, several academic experts admitted that they had little idea what would happen if one were to stick a hand inside the proton beam at the LHC. Professor Michael Merrifield put it succinctly: “That’s a good question. I don’t know is the answer. Probably be very bad for you.” Professor Laurence Eaves was also cautious about drawing conclusions. “[B]y the scales of energy we notice, it wouldn’t be that noticeable,” he said, likely with a bit of British understatement. “Would I put my hand in the beam? I’m not sure about that.”

Such thought experiments can be useful tools for exploring situations that can’t be studied in the laboratory. Occasionally, however, unfortunate accidents yield case studies: Opportunities for researchers to study scenarios that can’t be experimentally induced for ethical reasons. Case studies have a sample size of one and no control group. But, as the neuroscientist V.S. Ramachandran has pointed out in Phantoms in the Brain (1998), it takes only one talking pig to prove that pigs can talk. On September 13, 1848, for example, an iron rod pierced through the head of the U.S. railway worker Phineas Gage and profoundly changed his personality, offering early evidence of a biological basis for personality.

And on July 13, 1978, a Soviet scientist named Anatoli Bugorski stuck his head in a particle accelerator. On that fateful day, Bugorski was checking malfunctioning equipment on the U-70 synchrotron—the largest particle accelerator in the Soviet Union—when a safety mechanism failed and a beam of protons travelling at nearly the speed of light passed straight through his head, Phineas Gage-style. It’s possible that, at that point in history, no other human being had ever experienced a focused beam of radiation at such high energy. Although proton therapy—a cancer treatment that uses proton beams to destroy tumors—was pioneered before Bugorski’s accident, the energy of these beams is generally not above 250 million electron volts (a unit of energy used for small particles). Bugorski might have experienced the full wrath of a beam with more than 300 times this much energy, 76 billion electron volts.