Antimatter consists of subatomic particles that have the same mass as ordinary matter, but an opposite charge. CERN has previously generated antimatter, but never in a way that allowed careful study. This new anti-hydrogen beam, however, could change everything, including what we know about particle physics, because scientists have been able to successfully trap it.

CERN created the anti-hydrogen beam with an Antiproton Decelerator, which allowed them to mix antielectrons with antiprotons. They worked with hydrogen because it is the simplest element, consisting of just one proton and one electron.