There is likely little in the world of physics that is so accurately named yet exotically connotated as matter and antimatter. Matter is simple; it is all the stuff and material that makes up you and every physical object you can think of. Your body, chairs, planets, and atoms are all examples of matter. Antimatter is somewhat of an opposite; an antimatter particle is exactly the same as a matter particle, except for the fact that it has opposite charge. The normal matter proton, found in the nucleus of any atom, is positively charged, so the antimatter antiproton is negatively charged but equivalent in every other way. Scientists have recently confirmed, to a new level of accuracy, that this equivalence maintains for gravitational interactions, too.
A research team led by RIKEN, and including multiple international partners like CERN, published their results in Nature last week. The team used data from a separate experiment which looked at the charge-to-mass ratios of protons and antiprotons. With this information, the team found that gravity acted upon the two kinds of particles in the same way. In a RIKEN press release, project lead Stefan Ulmer described that through the charge-to-mass experiment, “…we were able to obtain a result that they are essentially equivalent, to a degree four times more precise than previous measures. To this level of CPT invariance, causality and locality hold in the relativistic quantum field theories of the Standard Model.” The second sentence is basically saying that our normal ideas of cause and effect and space hold in the scenario examined.
The motivation for studying the similarities and differences of matter and antimatter may not be apparent on the surface. After all, I was able to explain their differences in two sentences. It turns out that, despite the seemingly simple explanation that antimatter is just matter with an opposite charge, and the study’s results that gravity treats them the same, there is more to the matter-antimatter distinction. Despite being mirror images, our Universe is made up almost entirely of matter, with little antimatter to go around. Researchers hope to learn the reason for this discrepancy in their studies of matter and antimatter.
The results obtained by this team of researchers should be mirrored in future experiments, according to Ulmer. If those future experiments end up with contradicting findings, then this area could be a fruitful one to explore for more information about the differences between matter and antimatter and reasons for their universal discrepancy. If those experiments end up agreeing, then this study still serves as a confirmation and accuracy update of one of the properties of antimatter. Either way, we are hopefully one step closer to understanding that which makes up our Universe and us, too.
Article Image Source: CERN