The first results from the Muon g-2 experiment hosted at Fermilab show fundamental particles called muons behaving in a way not predicted by the Standard Model of particle physics. Announced on April 7, 2021, these results confirm and strengthen the findings of an earlier experiment of the same name performed at Brookhaven National Laboratory. Combined, the two results show strong evidence that our best theoretical model of the subatomic world is incomplete. One potential explanation would be the existence of undiscovered particles or forces. This video explains what a muon is, how the Muon g-2 experiment works, and the significance of this result. Muon g-2 first results press release: https://news.fnal.gov/2021/04/first-results-from-fermilabs-muon-g-2-experiment-strengthen-evidence-of-new-physics Fermilab home page: https://fnal.gov/ Muon g-2: https://muon-g-2.fnal.gov/ #gminus2 Credits: Writers: Scott Hershberger, Kurt Riesselmann Narrator: Lauren Biron Featured Scientists: James Mott, Saskia Charity, Jarek Kaspar, David Hertzog Producer/Editor: Ryan Postel Animators: Diana Brandonisio, Ian Krass, Ryan Postel Graphic Design: Diana Brandonisio