How can antimatter exist at all? What amount of math had to be done until someone realized they can create it?
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It’s a long story if you want to get the whole picture, so bear with me!
First, we found out that matter is made of little atoms. People had proposed this for a long time, at least since ancient Greece. Then in 1897, physicists discovered that atoms in matter can be split into two parts, one with positive charge and one with negative charge. They found this by trying to pass electricity through empty space in something called a vacuum tube and observing a stream of green substance coming out of the negative end (cathode) of the electric circuit. That’s how they knew that the stream is made of tiny negative charges, which we call electrons.
It turns out that electrical charges can be moved around by a magnet. If you hold a magnet near the green stream of electrons, the stream bends to one side. This fact will be important later.
In 1912, some physicists attached some instruments that can measure the amount of charged particles onto a balloon. They detected more and more charged particles as the balloons rose higher and higher into the atmosphere. These charged particles must’ve come from outside the Earth, and the physicists were sure they didn’t come from the Sun, as the experiment was done during a total solar eclipse, when the Moon blocked up the Sun completely. This was the discovery of cosmic rays.
By 1932, physicists had improved their instruments so cosmic rays could be detected from the ground instead of on balloons. They then tried to find out what these charged cosmic ray particles are. Using something called a cloud chamber, they could directly see the path of any charged particle passing through it, because it would leave a trail of bubbles through the cloud. They saw many trails coming from the sky—cosmic rays. But when they placed a magnet in the cloud chamber, they found that some cosmic ray particles left a curved trail that bent opposite to the expected direction for an electron, so it is positively rather than negatively charged! (Remember the magnet bending the green stream above?) This was the discovery of a new particle that is just as small as the electron but has the exact opposite charge as the electron. We call it the positron, the first discovery of antimatter!
From this point on, scientists gradually suspected that every “normal” particle that makes up regular matter (proton, neutron, etc.) has its own antiparticle (antiproton, antineutron, etc.), which has the same mass as the regular one but opposite charge. For example, the antiproton was discovered (produced) in 1955 by shooting lots of very fast protons towards a copper target and seeing what comes out.
When a regular particle touches its antimatter evil twin, the two would disappear into a burst of light (or other particles). This is why we don’t usually see antimatter around us and why it is so hard to make and keep around, because it would just destroy everything it touches.
To finish this part of the story, scientists believe that in the very early days in the history of the Universe, there were nearly equal amounts of matter and antimatter. However, since they’re all mixed together and touching each other, they kept destroying each other. At the end, only the tiny amount of remaining matter survived, making up all that we see in the Universe today. Why there were any remaining matter particles and how this whole process occurred is still a mystery that physicists are working on today.
As for what maths is needed to discover and learn about these things, here’s an incomplete list (and examples of their use):
* Algebra (to write down any formula or equation about the motion and behaviour of particles)
* Geometry (to figure out the shapes of trails made by particles and how to build measurement instruments)
* Differential equations (to describe and build electrical circuits)
* Multivariate calculus (to calculate the exact shapes of particle trails and how magnets affect them)
* Complex numbers (to describe electrical circuits; – to describe how electrons stay inside or get out of atoms using quantum mechanics)
* Linear algebra (also quantum mechanics)
* Quantum field theory (to describe how matter and antimatter particles disappear into light)
Most of the above are taught in a standard undergraduate physics curriculum. Quantum field theory is typically taught at the graduate level.
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