- What is antimatter?
- Discovery of antimatter
- Antimatter properties
- Where is antimatter found?
- What is antimatter for?
We explain what antimatter is, how it was discovered, its properties, differences with matter and where it is found.
What is antimatter?
In particle physics, antimatter is the type of matter made up ofantiparticles, instead ofparticles ordinary. It is a less frequent type of matter.
Antimatter is very similar to common matter, the only difference is in the electric charge of the particles and in some quantum numbers. Thus, an antielectron, also calledpositron, It is the antiparticle of the electron, which has the same properties except the charge, which is positive. Antineutrons, on the other hand, are neutral (like neutrons) but their magnetic moments are opposite. Finally, antiprotons differ from protons in that they are negatively charged.
By interacting, antimatter and matter annihilate each other after a few moments, releasing huge amounts ofEnergy in the form of high-energy photons (gamma rays) and other elementary particle-antiparticle pairs.
In studies ofphysical A distinction is made between particles and antiparticles using a horizontal bar (macro) over the symbols corresponding to theproton (p),electron (e) andneutron (n).
Atoms made up of antiparticles do not exist naturally in the nature because they would be annihilated with ordinary matter. Only a very small amount has been successfully created in experiments aimed at the formation of anti-atoms.
Discovery of antimatter
The existence of antimatter was theorized in 1928 by the English physicist Paul Dirac (1902-1984) when he set out to formulate a mathematical equation combining the principles of relativity Albert Einstein and the quantum physics by Niels Bohr.
This arduous theoretical work was successfully solved and from there the conclusion was obtained that there had to be a particle analogous to the electron but with a positive electric charge. This first antiparticle was called antielectron and it is known today that its encounter with an ordinary electron leads to mutual annihilation and the generation of photons (gamma rays).
Therefore, it was possible to think about the existence of antiprotons and antineutrons. Dirac's Theory was confirmed in 1932, when positrons were discovered in the interaction between cosmic rays and ordinary matter.
Since then the mutual annihilation of an electron and an antielectron has been observed. Their meeting constitutes a system known as positronium, half-life never exceeding 10-10 or 10-7 seconds.
Subsequently, at the Berkeley particle accelerator (California, 1955) it was possible to produce antiprotons and antineutrons through high-energy atomic collisions, following Einstein's formula of E = m.c2 (energy equals mass by speed of light squared).
Similarly, in 1995 the first anti-atom was obtained thanks to the European Organization for Nuclear Research (CERN). These European physicists managed to create an antimatter hydrogen or antihydrogen atom, made up of a positron orbiting an antiproton.
Antimatter properties
Recent research on antimatter suggests that it is as stable as ordinary matter. However, its electromagnetic properties are inverse to those of matter.
It was not easy to study it in depth, given the enormous monetary costs involved in its production in a laboratory (about USD 62,500 million per milligram created) and its very short duration.
The most successful case of antimatter creation in the laboratory lasted about 16 minutes. Even so, these recent experiences have led to the intuition that matter and antimatter may not have the exact same properties.
Where is antimatter found?
This is one of the mysteries of antimatter, for which there are many possible explanations. Most of the theories about the origin of the universe accept that in the beginning they existed proportions the like of matter and antimatter.
However, at present the observable universe appears to be composed solely of ordinary matter. Possible explanations for this change point to the interactions of matter and antimatter with the dark matter, or to an initial asymmetry between the amount of matter and antimatter produced during the big Bang.
What we do know is that natural antiparticle productions take place in the Van Allen Rings of our planet. These rings are located about two thousand kilometers from the surface and react in this way when gamma rays strike the atmosphere Exterior.
This antimatter tends to clump together, since there is not enough ordinary matter in that region to annihilate itself, and some scientists think that this resource could be used to “extract” antimatter.
What is antimatter for?
Antimatter does not yet have many practical uses in human industries, due to its very high costs and the demanding technology that implies its production and handling. However, certain applications are already a reality.
For example, positron emission tomography (PET) scans are performed, which has suggested that the use of antiprotons in cancer treatment is possible and perhaps more effective than current proton techniques (radiotherapies).
However, the main application of antimatter is as a source of Energy. According to Einstein's equations, the annihilation of matter and antimatter releases so much energy that a kilo of matter / antimatter annihilating would be ten billion times more productive than any chemical reaction and ten thousand times more than nuclear fission.
If these reactions can be controlled and harnessed, all industries and even transportation will change. For example, ten milligrams of antimatter could propel a spacecraft up to Mars.