Sep 29, 2023 (NHK) - An international group of scientists say they have observed antimatter falling downwards under the Earth's gravity.
The research that was published in the journal Nature on Wednesday deals with the long-standing question of whether antimatter resists gravity.
Matter is composed of protons and particles such as electrons. Antimatter consists of the same particles and mass, but with a reversed charge.
The researchers, many of them based in Canada, artificially created antihydrogen atoms using a giant particle accelerator near Geneva. About 100 antihydrogen atoms were trapped inside a vertical cylinder device.
After repeated experiments, the scientists observed that the antihydrogen atoms were mostly in the bottom half of the cylinder. They concluded that antimatter is affected by the downward pull of the Earth's gravity in the same way as matter.
Fujiwara Makoto, Senior Scientist at TRIUMF, Canada's national particle accelerator laboratory, is one of the two Japanese scientists in the group. He says he believes the finding has settled the question of whether antimatter falls downwards or moves upwards with gravity.
Observation of the effect of gravity on the motion of antimatter
