But in Carl Anderson discovered an antimatter partner to the electron — the positron — while studying cosmic rays that rain down on Earth from space. Over the next few decades physicists found that all matter particles have antimatter partners. Scientists believe that in the very hot and dense state shortly after the Big Bang, there must have been processes that gave preference to matter over antimatter. This created a small surplus of matter, and as the universe cooled, all the antimatter was destroyed, or annihilated, by an equal amount of matter, leaving a tiny surplus of matter.
And it is this surplus that makes up everything we see in the universe today. Exactly what processes caused the surplus is unclear, and physicists have been on the lookout for decades. The behaviour of quarks, which are the fundamental building blocks of matter along with leptons, can shed light on the difference between matter and antimatter. The up and down quarks are what make up the protons and neutrons in the nuclei of ordinary matter, and the other quarks can be produced by high-energy processes — for instance by colliding particles in accelerators such as the Large Hadron Collider at CERN.
Particles consisting of a quark and an anti-quark are called mesons, and there are four neutral mesons B 0 S , B 0 , D 0 and K 0 that exhibit a fascinating behaviour. Most of the pairs would be annihilated, but a few normal particles would remain. It wouldn't have to be much: Just one particle in a billion would be enough to lay the foundations for all the stars and galaxies that we see today.
It would indeed have to be a very peculiar set of conditions to cause such an imbalance. Our universe is governed by rules of how particles and forces should interact and behave.
It's these rules that lay the framework for all the wonderful interactions that make up the richness of everyday life. But sometimes rules need to be broken, as in the case of the early universe. After all, it's those same rules that say that the divergence between matter and antimatter ought not to be in the first place. Whatever interaction, whatever process, led to matter's ultimate victory had to be strange indeed.
It had to start with producing not just an excess quantity of regular matter, but also an excess quantity of charge to counterbalance it.
Otherwise, because total charges must stay the same throughout a process, that matter-loving route would've been perfectly balanced by a twin antimatter-loving road. Plus, this process had to happen during a sharp boundary, when the infant cosmos was transforming rapidly from one state to another.
It's only there that the physics would permit such a rule-breaking violation to take place; otherwise a universe in equilibrium would just end up balancing all interactions out anyway.
Is there anything in all of known physics that could make the antimatter go away? Well, maybe. There are some hints and suggestions buried in rare particle interactions involving the weak nuclear force.
We understand these interactions only dimly, especially the way they would occur in the early universe, but even there our best guess for its matter-favoring ability put it far, far below the minimum needed to explain our present situation.
The origins of the asymmetry between matter and antimatter is an outstanding problem in physics. How do supermassive black holes grow so large? Cosmos: Origin and Fate of the Universe. Astronomy's Moon Globe. Galaxies by David Eicher. Astronomy Puzzles. Jon Lomberg Milky Way Posters. Astronomy for Kids. Sign up. Table of Contents Subscribe Digital Editons. A chronicle of the first steps on the Moon , and what it took to get there.
The Magazine News Observing. Photos Videos Blogs Community Shop. Sign up! Follow us: Facebook Twitter. During the first fractions of a second of the Big Bang , the hot and dense universe was buzzing with particle-antiparticle pairs popping in and out of existence.
If matter and antimatter are created and destroyed together, it seems the universe should contain nothing but leftover energy. Nevertheless, a tiny portion of matter — about one particle per billion — managed to survive. This is what we see today. In the past few decades, particle-physics experiments have shown that the laws of nature do not apply equally to matter and antimatter.
Physicists are keen to discover the reasons why. Researchers have observed spontaneous transformations between particles and their antiparticles, occurring millions of times per second before they decay.
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