We learn it at high school: Release two objects of different masses in the absence of friction forces and they fall down at the same rate in Earth’s gravity. What we haven’t learned, because it hasn’t been directly measured in experiments, is whether antimatter falls down at the same rate as ordinary matter or if it might behave differently. Two new experiments at CERN, ALPHA-g and GBAR, have now started their journey towards answering this question.
Which falls faster in a frictionless gravity field – a 1 pound ball bearing or a 1 pound anti-matter feather? Answer: We don’t know yet, but we’re aiming to find out.