Oh boy this one is a wild one! Everyone knows matter, you’re surrounded by it. Anything you can touch and takes up space is matter. What is antimatter though?
Oh how the word antimatter has been thrown around in science fiction movies and in casual conversation. But it is very much a real thing. Perhaps you already knew this but how much do you actually know about it?
When was it first discovered?
The theorized concept of antimatter was proposed by Karl Pearson between the 1880’s and 90’s. The term antimatter was first used not by Pearson but by Arthur Schuster in 1898. He hypothesized the existence of anti-atoms.
It wasn’t until Paul Dirac came in 1928 to provide a modern theory on antimatter. Charles Janet envisioned an entire periodic table of antimatter. It was only later discovered a mere 3 years later by Carl D. Anderson. Anderson only discovered positrons (a oppositely charged electron).
What is it made of?
Well the general principal is easy to understand. Antimatter much like matter is made up of particles. In matter you have protons which has a positive charge and an electron with a negative charge. You also have a neutron but we won’t be talking about that much.
In antimatter the charges are switched. The proton is now positive and is now called an anti-proton and the electron is now positively charged and is called a positron. Perhaps one of my favorite names for a particle.
What does it do?
A very interesting behavior occurs with antimatter. Usually when something has the word ‘anti’ in front of it one might think it likes to get rid of what ever the following word is. Anti-tank rounds get rid of tanks. Well antimatter has a real knack for annihilating itself by crashing into a piece of matter.
This is because of the oppositely charged particles which causes them to be extremely attracted to one another. Once the particles collide they release gamma rays which as some may know are highly energetic photons. Sometimes neutrinos are also produced in this highly energetic annihilation.
In the Star Trek universe such reactions power the engines of the ships. However modern technology is far from producing the amount needed for any energy gain.
The making of antimatter?
There is two methods natural and artificial.
Positrons can be created via beta decay of radioactive isotopes. Antineutrinos can also be created by radioactive beta decay. If you remember beta decay is when an electron is emitted.
Cosmic rays can also create a variety of anti-particles. They can also be contained due to the electromagnetic forces of such rays.
The artificial means of producing antimatter involves some physics sorcery. In order for scientists to produce a antihydrogen atom you must go to a facility like CERN. This is where the Large Hadron Collider is located. They introduce antiprotons to positrons and create antihydrogen. The process is much more in depth than that but I’d like to keep this of a reasonable length.
The positrons are created using the beta decay of radioactive isotopes. The anti-protons are created by proton on proton collisions.
The CERN facility could produce 1 gram of antimatter in 100 billion years, that is if all of the antiprotons formed antihydrogen. The cost of 10 milligrams of positrons is around $250 million dollars in 2006 as stated by Gerald Smith.
The energy required is enormous compared to the energy released when these particles collide with matter. The most difficult part about making antimatter is having around long enough to study. It immedietely wants to annihilate itself. So therefore it must be kept in a magnetic field shaped much like a bath tub. CERN was able to capture and hold antihydrogen for about 15 minutes.
What they found was similar properties to normal hydrogen. They saw that it had a similar light spectrum. They energized the antihydrogen with a laser and once the positrons decreased their energy levels released characteristic wavelengths of light. Not enough to see of course but enough to be detected.
What could we use this stuff for?
There are current uses in the medical field like positron emission tomography or PET. There is always the fuel industry. The future might hold antimatter rockets propelled by the immense energy density of antimatter and matter collisions allowing for interstellar flight. And of course humans naturally want to blow stuff up with it but production simply would’t meet demand.
Physics remains to be one of my favorite subjects and probably will be till my last day on Earth. Who knows what amazing technology lies in the future that will be stumbled upon or keenly invented by the future generations. The future looks bright for technology. I hope that a major breakthrough happens within my lifetime which I suppose it already has with antimatter. Oh what a time to be alive!
Antimatter (physics) Encyclopedia Britannica