Scientists Excited by Potential New Force of Nature 3 hours ago The test track scientists are using to observe muon particles outside of Chicago, Illinois at the Fermilab. (Reidar Hahn/Fermilab via AP) Share share The URL has been copied to your clipboard 0:00 0:06:20 0:00 Have you ever heard of a muon? A muon is a very small particle similar to an electron. Electrons and protons are parts of the atoms that make up all matter. Muons were discovered during an experiment in 1936. Until now, most physicists have only been able to study muons for an extremely short period of time: two microseconds. There are one million microseconds in one second.