For the first time, scientists have observed antimatter particles -- the mysterious twins of the visible matter all around us -- falling downwards due to the effect of gravity, Europe's physics lab CERN announced on Wednesday.
The experiment was hailed as "huge milestone", though most physicists anticipated the result, and it had been predicted by Einstein's 1915 theory of relativity.
It definitively rules out that gravity repels antimatter upwards -- a finding that would have upended our fundamental understanding of the universe.
