Here’s a look back at some of the spectacular stories science served us in 2021, including tardigrades shot from a pistol, the world’s largest offshore wind turbines, nuclear fusion records, radical new materials, and potty-trained cows.
At CERN, a particle was observed switching between matter and antimatter
In June, a group of Oxford physicists stated that data from the Large Hadron Collider suggests that a subatomic particle known as the charm meson can switch between being matter and antimatter, which could explain why the cosmos averted annihilation soon after the Big Bang.
According to Oxford physicists studying data from the Large Hadron Collider, a subatomic particle has been discovered that can transition between matter and antimatter. It turns out that a seemingly insignificant weight differential between two particles could have rescued the cosmos from annihilation shortly after it was born.
Antimatter is the “evil twin” of regular matter, but it’s remarkably similar — the only major difference is that antimatter has the opposite charge. That means that if matter and antimatter particles collide, they will annihilate one another in a blast of energy.
To make matters more complicated, some particles, such as photons, are actually antiparticles of themselves. Others have been observed to exist as a strange blend of both states at the same time, according to the quantum quirk of superposition (best exemplified by Schrödinger’s cat’s thought experiment.) This means that these particles alternate between matter and antimatter states.
The charm meson is the latest particle to enter that exclusive club. This subatomic particle is made up of a charm quark and an up antiquark in normal matter, and a charm antiquark and an up quark in antimatter. Normally, both states are maintained separate, but new research suggests that charm mesons can transition between them spontaneously.
The fact that the two states have somewhat differing masses ultimately revealed the truth. The change is only 0.00000000000000000000000000000000000001 grams.
Physicists at Oxford University extracted this highly exact measurement from data collected during the second run of the Large Hadron Collider. In proton-proton collisions at the LHC, charm mesons are formed, and they usually only travel a few millimeters before decaying into other particles.
The scientists discovered that differences in mass are the major factor that determines whether a charm meson develops into an anti-charm meson or not by comparing those that tend to go further with those that decay sooner.
This minuscule discovery could have massive repercussions for the universe. According to the Standard Model of particle physics, the Big Bang should have produced equal amounts of matter and antimatter, which would have interacted and annihilated over time, leaving the universe very empty. Obviously, this did not occur, and matter came to dominate; nevertheless, what created this imbalance?
According to one theory proposed by the new finding, particles like the charm meson will transition from antimatter to matter more frequently than they will migrate from matter to antimatter. Investigating if this is true – and, if so, why – could be a key to unlocking one of science’s deepest riddles.