Can we add matter and antimatter to the universe? [closed]

Question

Sorry if this is a basic question, or there is a glaringly large hole in my reasoning, I am not smart, and saw a documentary and did some googling, after which I decided to ask people with actual experience.

I read about the Big Bang resulting in a lot of matter and antimatter, and if we added it all up, it should equal 0, which is what there was before.

By this reasoning (matter and antimatter cancels out), could we add matter and antimatter? 0 + (-x) + (+x) = 0, and if we managed to separate the two (using gravity, maybe), could we end up with extra matter, but also extra antimatter, which can be ejected into space (or somewhere else, like another planet, where it will not affect us), we could end up with more stuff on Earth, but less stuff elsewhere.

Some issues with what I have just described:

We might not be able to siphon the antimatter and matter away from each other (or control anything about this at all).

I also heard that when antimatter and matter combine, it releases energy in the form of light. I feel like this violates the conservation of energy. If (-x) + (+x) = 0, I do not see where the light came from, unless there is some kind of negative energy released, like anti-light or something like that.

Also, somewhat related– CERN says there is some kind of matter-antimatter imbalance.

How plausible is what I have just described? Please, no hate or rude comments, I have no idea about anything physics-related (I am a minor and know next to nothing). If what I have described is not possible, could you provide a quick explanation (antimatter is a hoax, etc). I am not concerned with the fact that we have no technology to do this yet; I was curious as to whether such a thing could be possible.

If any of my facts or assumptions are wrong, kindly tell me.

Answer 1

You are correct that matter and anti-matter can be added to the universe, but the law of conservation of energy is still obeyed. For instance, in the right circumstances two photons (packets of light, not matter) can be combined to produce an electron and an anti-electron ("positron"). ("Pair production", if you want to research it further.) The energy of the original photons is equal to the energy of the electron and positron. The electron and positron can recombine ("Annihilation") and become two photons again. In fact that is nearly inevitable, and particles of anti-matter cannot be kept around for long unless they are very cleverly trapped.

It would seem reasonable that the big bang would have produced equal amounts of matter and anti-matter. However, everywhere we look in the universe we see a relatively large abundance of matter and almost no anti-matter. The cause of this asymmetry is unknown. Congratulations, you just stumbled upon one of the greatest unsolved problems of modern science.

Answer 2

What you are thinking about depends very much on the basic theory of nature, called Quantum Mechanics, that is not intuitively evident, and also on the theory of special relativity, that is also a twentieth century discovery. So in order to really understand the subject you should start studying physics.

In layman terms:

1. mass is equal to the weight of an object around us, as the object interacts with the force of gravity. Objects can gain kinetic (moving) energy, which is equal to the to $E_k= 1/2 m v^2$ where $v$ is the velocity of the object. In the theory of special relativity, the rest mass of an object is also equal to energy. The mass energy is stable and invariant in everyday reactions but can be accessed in nuclear reactions, as in the atomic bomb.

2. At the level of the tiny particles composing all matter, from electrons to protons etc, it was found experimentally that certain numbers , called quantum numbers, distinguish particles from antiparticles: antiparticles have the exact same mass as the particles,but opposite quantum numbers. When particle meets antiparticle, quantum numbers add up to zero and all the energy, including the mass energy is released and the particles disappear, that is called annihilation . If the kinetic energies are low enough, the annihilation leads only to photons, the particles that make up the light and are their own antiparticles,and have zero mass. If the energies are high , as in the accelerators at CERN, the resultant energy from the annihilation makes new pairs of particle-antiparticle.

At CERN they studied proton antiproton annihilation in two colliding beams for years, the results leading to the present theory of the standard model of particle physics. Thus, yes, at large expense one can separate particles from antiparticles , and maybe in space, create an antiparticle lump, but it would be stable only as long as it does not meet normal mass. What you propose would be possible at enormous expense and effort, but to no useful effect really.

The matter antimatter imbalance is the observed effect that our universe is composed of matter. That is why it is a problem for the models of the Universe to explain how antimatter disappeared and only matter in bulk exists, as our present particle theory does not offer enough of an explanation. A basic theoretical problem for future physicists to solve.