Ripping the Air a New One

I've finished two days of my proton therapy, and I'm feeling fine so far, but the driving and treatment take up a lot of my day, so I might not manage a real post until this weekend.  This is just a quick post to point out two interesting side-effects of the treatment.  While the beam is directed at my head (as opposed to spine) I can see white spots with my eyes closed, and smell a strange odor.  I asked one of the technicians about this today, and she told me that both are due to the protons interacting with parts of my head.  I didn't get any details on the light – just some reaction with the optical parts of the brain – but the smell is caused by the protons ionizing the air in my sinuses.  Coincidentally, we're currently having a thunderstorm here, which also involves ionizing air, in the form of lightning.  Pretty cool (and admittedly terrifying) stuff...