But a small imbalance remained, in the form of an excess of matter, of the order of one extra matter particle per billion matter- antimatter particle pairs. The cosmic microwave background radiation which pervades the universe today represents the remains of the energy produced by this wholesale annihilation of the matched particle-antiparticle pairs. It is assumed that, very early in the life of the universe, in a process known as baryogenesis, massive numbers of particles and antiparticles were created and did in fact annihilate each other. Which begs the question of why this huge apparent imbalance exists, and why all matter and antimatter did not just annihilate each other completely very early in the history of the universe (and therefore, ultimately, why we are here at all!) While it is technically possible that substantial amounts of antimatter do exist somewhere in the universe, isolated in some way from normal matter, no substantial quantities of antimatter have actually been discovered. The tiny quantities of antimatter which scientists have managed to create in the laboratory have always been accompanied by an equal quantity of normal matter, and the two tend to cancel each other out almost immediately. This explosive annihilation mirrors the huge energy required to produce the matter- antimatter pairs in the first place.įor example, the high- energy cosmic rays which regularly impact the Earth's atmosphere produce minute quantities of antimatter in the resulting particle jets, which are immediately annihilated by contact with nearby matter. However, when matter and antimatter meet, they completely annihilate each other in a brilliant flash of light produced by extremely high- energy gamma photons. Pair production and pair annihilation of hydrogen and antihydrogen particles With the development of super-high-acceleration machines after World War II, other particles (such as protons and neutrons) and their respective antiparticles were created, and even stored in magnetic “bottles”. This antimatter, then, is the “mirror image” of matter, and the antiparticles of which it is composed are the mirror images of normal particles, being the same size but having opposite electrical charge.ĭirac’s equations also predicted that, if enough energy could be concentrated, an anti electron (always accompanied by an electron in order to preserve the overall electrical charge) could in theory be produced where none had existed before! In 1933, Carl Anderson successfully demonstrated the appearance of this hypothetical anti electron (which he called the positron), and definitively showed that matter could in fact be created in the laboratory in a controlled experiment.
For each of his theoretical equations, there appeared to exist another associated solution, with all the properties reversed, which did not seem to physically exist in the known universe. The British physicist Paul Dirac first predicted the existence of antimatter in 1928.
The apparent asymmetry of matter and antimatter in the visible universe is one of the greatest unsolved problems in physics. Thus, for every quark produced in the early stages of the Big Bang, there would also have been an anti quark for every electron, a positron (the antiparticle of the electron) etc. According to theory, the Big Bang should have produced matter and antimatter in equal quantities. - The Big Crunch, the Big Freeze and the Big RipĪnother area which perhaps needs some additional explanation is the concept of antimatter, and why our universe consists almost entirely of matter and hardly any antimatter.- Accelerating Universe and Dark Energy.- The Expanding Universe and Hubble’s Law.- The Big Bang and the Big Crunch Introduction.Main Topics > The Big Bang and the Big Crunch > Antimatter Topic Index:
A Few Random Facts Where in the universe is the Earth? How fast are we traveling through space? How fast does light travel? How far is it to space, the Moon, the Sun, the stars, etc? How many stars are there? How does the Sun shine? What different types of stars are there? What is the human body (and the Earth, the Sun, the Universe) made of? How many molecules/atoms are there in each cubic meter? What if the history of the universe were squeezed into the period of one year? What are the coldest and the hottest objects in the universe? What is the electromagnetic spectrum? What is a planet? What is a dwarf planet? Why do the planets orbit the Sun?
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