ASKING THE IMPORTANT QUESTIONS: Does antimatter fall upwards? New CERN gravity experiments aim to get to the bottom of the matter.

Predictions say that antimatter particles should mostly follow the same rules as their normal counterparts, but it’s worth double-checking to be sure – after all, any other differences could bring into question the entire Standard Model of particle physics. A few years ago, the CERN team trapped and studied the optical spectrum of antihydrogen for the first time and, breathing a big sigh of relief, found that it was identical to that of hydrogen.

Another fundamental question is whether antimatter reacts to gravity the same way. Again, predictions say it should fall like regular matter, but there’s about a one-in-a-million chance that it actually falls up instead. So far, antimatter has only been studied while suspended in an electromagnetic trap, since letting it fall to the bottom (or top?) of any normal container will destroy it.

Two new experiments at CERN are ready to test out the problem. In both cases, after the antimatter is created, the scientists will switch off the electromagnetic traps holding it, then examine where in the tube the annihilations occur. That will allow them to measure the effects of gravity on antiatoms, and see if there are any discrepancies.

Fascinating.