Eli5 what is anti matter?


Eli5 what is anti matter?

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No one knows.

But astro-physists noticed that some stars in the outskirts of galaxies are moving way, way faster than they should be, given the forces of gravity acting upon them by regular matter which is detectable. They therefore theorized that there must be other matter…a lot of it…which they’ve so far been unable to detect, but which is causing gravitational pull on these unexplainably fast moving stars.

Edit…all that is wrong. I was thinking of dark matter.

Anti Matter is basically the mirror equivalent to normal matter. Matter (everything from air molecules, steel, your skin, water, farts) consists out of atoms. Atoms (as a very easy simplification) consists out of protons (positive charge), often neutrons (no charge) and electrons (negative charge) … with antiprotons having a negative charge and antielectrons (called positrons) having a positive charge.

Antimatter is at least right now incredibly difficult and expensive to create, the theoretical value of one gram of Antimatter is somewhere in the 50 trillion USD range. So any kind of mass production is out of the question, and this is perhaps for the better, because antimatter, aside from its very interesting physical properties, known for causing one of the most violent reactions known to humanity: the matter / antimatter annihilation. Would such an annihilation of equal mass of matter / antimatter happen the result would be on par or easily surpass the biggest nuclear weapons ever created.


In math you have positive numbers and negative numbers right, and when you add an positive number and a negative number with the same absolute value they add up to 0.

Just like that you have regular matter, and it’s opposite, antimatter. Just like positive and negative numbers regular matter and antimatter anihillate eachother when they meet, producing insane ammounts of energy.

In figuring out what everything in the universe is made of, we have discovered a group of particles which, as far as we can tell, aren’t made up of anything simpler. We call these particles “elementary particles” and they are:

* Quarks (up, down, charms, top, bottom)
* Electron family particles (electrons, muons, tau)
* Neutrino family particles (electron neutrinos, muon neutrinos, tau neutrinos)
* Force particles (gluons, photons, Z/W bosons, Higgs boson)

Naturally, you might ask how can we tell what kind of particle something is? Well, there are a handful of properties that essentially determine what a particle is:

* Mass
* Spin
* Electromagnetic charge

And that’s pretty much it. If you have a particle that is 9.1093837015×10^(−31) kilograms, has a spin of 1/2, and an electric charge of -1, then it’s an electron.

We have also discovered the existence of particles whose properties match those of the particles listed above, except the electromagnetic charge is different. For example, there exists a particle that is 9.1093837015×10−31 kilograms, has a spin of 1/2, and an electric charge of +1.

We call these particles anti-particles, as they appear to be the “opposite” of the particles whose mass/spin they match, and annihilate them on contact. In some cases they get a special name (e.g. the anti-particle of the electron is called the positron), but generally it’s just “anti-” (e.g. anti-up quark).

As far as we can tell, anti-particles obey all the same physical laws as normal particles, they just have opposite electrical charges.

Antimatter is exactly the same as normal matter, just “opposite”. Normal hydrogen for example is composed of a proton and an electron, with the proton being positively charged and the electron being negatively charged.

For antimatter the positively charged proton would be replaced by a negatively charged antiproton. Same mass, same strength of charge, just flipped. The negatively charged electron would also be replaced by a positively charged positron. Again identical to an electron except with opposite charge.

Antimatter seems to behave exactly the same as normal matter we are familiar with, at least as far as we can tell. This means we would expect all the same elements to be made, and even chemical reactions to work the same with antimatter. Of course we can’t test this very well because handling antimatter is very difficult since if it encounters normal matter they annihilate each other and release huge amounts of energy. Making antimatter is very difficult and can only be produced in small quantities so the testing we can do so far is limited.

And yes, it is a bit strange that matter is the way it is and not the flipped antimatter version. Scientists are still trying to figure out why the universe seems biased towards one kind (the one we are familiar with).