Quantum muon beam at Paul Scherrer Institute tests Einstein’s gravity law

Image: Markus Fischer / Paul Scherrer Institute · ethz.ch Researchers at ETH Zurich and the Paul Scherrer Institute are artificially producing an intense, cold beam of muonium, an exotic atom containing a second-generation antiparticle, in an attempt to rigorously test a cornerstone of Einstein’s theory of gravity. The team aims to measure whether Earth’s gravitational pull acts on muonium in the same way as it does on ordinary matter, a question that could reveal the existence of a fifth fundamental force. “We have taken an important step towards carrying out an exciting…