## Scientists are about to test Einstein’s gravity with exotic matter Does gravity affect every type of particle in exactly the same way? Researchers at ETH Zurich and the Paul Scherrer Institute (PSI) in Villigen are preparing an experiment that could test that fundamental assumption using one of nature's more unusual particles. "We have taken an important step towards carrying out an exciting experiment on this topic," says the professor of physics: "We want to measure the gravitational interaction of the muon." The familiar matter that makes up people, planets, and nearly everything around…