This video is about how to create muons in a particle accelerator via bombardment of heavy nuclei with protons, which results in creation of charged pions (plus and minus). The pions then decay into muons and mu neutrinos, and the muons then decay into electrons or positrons and more neutrinos. Muons also form in the upper atmosphere due to cosmic rays, and the uses of muons includes experimental tests of time dilation in special relativity, catalyzing muonic cold nuclear fusion, and more.