For the first time in history, scientists may be able to explain why matter makes up more of the universe than antimatter, according to a recent study published in the journal Nature.
Physicists at CERN’s Antihydrogen Laser Physics Apparatus (ALPHA) in Switzerland beamed lasers onto particles of antihydrogen — the antimatter counterpart to normal hydrogen — to see how light interacted with the strange material.
Antimatter is, as the name suggests, the direct opposite of matter. For example, while ordinary electrons have a negative charge, the electrons in antimatter have a positive one. As a result, the Standard Model of physics states that both elements should be opposed in every way.
If this were true, however, both matter and antimatter would have been created equally during the Big Bang. As this did not happen, researchers believe matter had a small edge that allowed it to permeate throughout the universe, The Christian Science Monitor reports.
In the study, the team recreated antimatter by putting antiprotons and positrons — the antimatter counterparts of protons and electrons — together. They then held the particles inside a vacuum contained by a strong magnetic field.
This allowed the researchers to trap the atoms for more than 16 minutes, giving them enough time to closely observe antimatter for the first time. They used 14 antihydrogen atoms to shine a laser onto the material and found that the light reflected off it in the same way it would reflect off a hydrogen atom.
This discovery is important because it shows that spectroscopy — the study of the interaction between light and matter — can be conducted on antimatter. This means that researchers may be able to one day build a full spectral analysis of antihydrogen in order to determine the key difference that allowed matter to win out over antimatter after the Big Bang.
“The existence of antimatter is well established in physics, and it is buried deep in the heart of some of the most successful theories ever developed,” said study co-author Mike Charlton, a professor at Swansea University, in a statement. “But we have yet to answer a central question of why didn’t matter and antimatter, which it is believed were created in equal amounts when the Big Bang started the Universe, mutually self-annihilate?”
Researchers hope this experiment will be the first step towards understanding the distribution of matter throughout the universe.
“To get some sense of the importance of this discovery, we need to understand that it has been 30 years in the making and represents the collaborative work of hundreds of researchers over the years,” Charlton added. “Inquiries into this area of physics started in the 1980s and this landmark achievement has now opened the door to precision studies of atomic antimatter, which will hopefully bring us closer to answering the question of why matter exists to help solve the mystery as to how the Universe came about.”