If antimatter falls up, it could explain dark energy
CERN experiment will soon confirm
It is surprising that, while antimatter was first observed in 1932, we still don’t know if it falls up or down. That is all about to change, however, as the AEgIS experiment at CERN, the big European home of the Large Hadron Collider, is on track to test a result that could shake the foundations of physics. If we do find it falls up, that could solve a lot of questions we have about the universe like why is there more matter than antimatter and undo some assumptions like whether the universe had a beginning.
At CERN, antihydrogen can be produced from the particle accelerator. This stable atom has a, for all purposes, infinite lifetime. Knowing how it behaves in a gravitational field might reveal whether any violations to our fundamental understanding of nature occur with antimatter. Typically, these antihydrogen atoms, when produced, will be traveling near the speed of light and will not show much tendency to fall. New mechanisms will allow those antihydrogen atoms to be slowed using lasers and magnetic traps, allowing measurements of their behavior in gravity.
For decades, physicists have believed that antimatter must behave the same way in a gravitational field as normal matter from purely theoretical arguments. The nuclei of atoms, they argue…
