Antimatter Feels Gravity Just like Matter

Abstract

T hrow a ball into the air and the pull of Earth’s gravity will bring it crashing back down. But what about a ball of antimatter? Will it fall in the same way, or does it somehow experience gravity differently? Physicists have been exploring such questions for nearly a century but, until now, there had been no direct experimental test of antimatter in free fall. Releasing the results of observations of free-falling antihydrogen atoms, the Antihydrogen Laser Physics Apparatus (ALPHA) Collaboration at CERN in Switzerland shows that the particles experience the same gravitational pull as ordinary matter as they accelerate to Earth [1]. The collaboration says that the experiments are a landmark test of the weak