A UK-supported collaboration at the CERN Antimatter Factory in France has shown for the first time that antimatter responds to gravity in the same way as matter.

Normal matter is what makes up stars, planets, and human beings.

What makes antimatter different from normal matter is that it has an opposite electric charge.

The ALPHA collaboration, a group comprised of global academics including professors from Swansea University, and the University of Manchester and the Cockcroft Institute, has been working to discover the nature of antimatter since its launch in 2005.

Now, with a paper published in the journal Nature, ALPHA has shown that, within the precision of an experiment, atoms of antihydrogen fall to Earth in the same way as their matter equivalents.

The group noted that although the prevailing view is that antimatter should behave in the same way as matter in response to Earth’s gravitational pull, direct observations have been lacking until now, owing to challenges in creating carefully controlled experimental conditions.

ALPHA spokesperson professor Jeffrey Hangst, who founded the ALPHA collaboration and is an experimental particle physicist at Aarhus University, Denmark, described the observations as a “milestone in the study of antimatter”.

“In physics, you don’t really know something until you observe it,” he said. “This is the first direct experiment to actually observe a gravitational effect on the motion of antimatter.”

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