Oh-My-God particle

I worked on the child and grandchild of this experiment, HiRes and Telescope Array as an undergraduate and a bit as a postgraduate at the University of Utah. Currently I work with the Fermi Gamma-Ray space telescope as a "science janitor". The reason it's called the Oh-My-God particle is because it kind of smashed through the GZK limit ( http://en.wikipedia.org/wiki/Greisen%E2%80%93Zatsepin%E2%80%... ) There's a few particles near this energy hitting the earth every day, the flux is just very, very low…

Hey this is the field I did my PhD in! Some fun facts: * The flux of particles in this energy regime is so low that you get about 1 per square kilometer per century, so studying them necessitates doing really wild stuff like instrumenting a patch of land the size of Rhode Island. See: https://en.wikipedia.org/wiki/Pierre_Auger_Observatory * These particles are so energetic that in their frame the nominally low-energy photons that comprise the cosmic microwave background appear as an impenetrable…

I wish the article included a bit more info about the significance of the particle, instead of just describing how energetic it was. For example, it never expands on this, which is IMO the most interesting sentence on the page: > The particle's energy was unexpected and called into question theories of that era about the origin and propagation of cosmic rays.

> in other words, a subatomic particle with kinetic energy equal to that of a 5-ounce (142 g) baseball traveling at about 100 kilometers per hour (60 mph) Similar energy but, luckily for us, completely different impact dynamics: a myriad of small interactions along its path in the atmosphere and in the Earth (I don't know the maximum depth, maybe it's even possible for it to traverse the planet), releasing energy a bit at a time, instead on one single…