Antimatter falls down due to gravity just like regular matter

Scientists trapped antihydrogen atoms using strong magnetic fields and then released them to watch them fall under the influence of gravity. Credit: U.S. NATIONAL SCIENCE FOUNDATION

A research conducted by scientists using the Antihydrogen Laser Physics Apparatus (ALPHA) at the European Council for Nuclear Research (CERN) has confirmed that antimatter behaves similarly to matter in gravitational fields.

Previously, some researchers had speculated that antimatter could repel gravity and move upward, a possible explanation for the lack of antimatter in the observable universe. However, the concept of ‘Antigravity’ for antiparticles has now been refuted by experimental results.

The weak equivalence principle (WEP) in the ‘General Theory of Relativity’ published by Albert Einstein requires that objects with mass, independent of their internal structure, behave identically under a gravitational field.

The team of researchers used ‘antihydrogen’ atoms to demonstrate antimatter motion under the Earth’s gravitational field.

The neutral antihydrogen atoms were first trapped by magnetic field in ALPHA and then released from the magnetic confinement to observe its motion. The antihydrogen atoms conformed to the gravitational attraction of the Earth and the said atoms fell towards the Earth in the same way as the hydrogen atoms.

Antimatter, which is the twin of regular matter with opposite properties, annihilates when it comes in contact with matter, and releases powerful amounts of energy. The experiment involved observing the behavior of antihydrogen atoms as they escaped the magnetic trap, with about 80% of the atoms destroyed at the bottom of the trap, indicating that antimatter falls to the bottom due to gravity.

The results are consistent with the general theory of relativity published by Einstein in 1915. At that time the concept of antimatter was non-existent and Einstein was unaware of the antimatter concept. The first antimatter (positron) was observed in 1932, confirming Dirac’s prediction in 1928.

The general theory of relativity has been tested many times since its publication, for example, proving the bending of light by a massive object in the solar eclipse of 1919, observation of gravitational waves in 2016, etc. However, the concepts of dark matter and dark energy are still developing and the effects of gravity on them have not yet been revealed And so research on exotic particles in gravitational fields must continue.

These findings have important implications for understanding the nature of antimatter and may lead to new discoveries in various fields.

The results are published in a journal Nature.