Anti Gravity - does anti matter fall upwards? That question is one of the remaining mysteries about a type of matter so opposite to the “normal” world around us. Measurements taken at the ALPHA experiment in Cern have now gotten us a little closer to an answer, although a definitive yes or no is still beyond our reach.
Physicists have speculated about the answer for decades, but there’s been little data to feed those efforts. Finding the answer has proved to be an experimental difficulty. Antimatter is hard to wrangle: it annihilates as soon as it comes into contact with ordinary matter. Although electromagnetic fields can be used to steer charged antimatter particles quite easily, the forces involved can easily overwhelm any gravitational signal you might hope to see. […] Despite those challenges, physicists have started making inroads with the stuff. In a paper published today in Nature Communications, a team working on the ALPHA experiment at CERN is reporting the first direct measurement of antimatter’s reaction to gravity.
The scientists were able to bound the problem: gravity either “pulls” anti matter no harder than 100x the force experienced by normal matter, or repulses it no more than 65x the force experienced by normal matter. That’s still a lot of wiggle room, but there are good indications that more precise measurements will be possible in the near future.