this post was submitted on 27 Sep 2023
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Hmm interesting. I wondered if it would be attracted or repelled by matter. It does annihilate when it comes in contact with mater, right?
The reason antimatter is "anti" is that an antiparticle has the opposite charge of its non-anti counterpart. Electrons have a negative charge, while their antiparticles, positrons have a positive charge. And since opposite charges attract, well, I think you can figure it out from there.
And yes, matter/antimatter interactions result in annihilation.
What exactly does "annihilation" mean in this context. Do both "atoms" give off energy and convert to sub atomic particles? Does one atom kind of "win" over the other and undergo fission instead of complete annihilation?
At this tiny scale, energy and mass are essentially equivalent. So when we say that matter annihilates, we mean that they transform into pure energy (in this case, as photons of light). They don't break into subatomic particles, because that still counts as mass. They just simply cease to exist.
As a side note, the "conversion rate" of mass into energy (and vice versa) is governed by Einstein's E=mc^2. All this equation means is that it takes a ridiculous amount of energy to create a small amount of mass, and vice versa, it only takes a small amount of mass to create a ridiculous amount of energy. Because antimatter annihilates completely (ie, 100% of its mass, as well as 100% of the regular matter's mass, gets converted into energy), antimatter is currently the most explosive thing known to mankind
Ok that makes sense.
Man that's pretty wild to think about. If antimatter was created at the same time as matter in the same quantity and distribution, then why are we here. Why didn't the entire universe essentially cancel itself out? Was there some factor that benefited regular matter or hindered antimatter? Is there some level of chaos on the atomic or subatomic scale that played in regular matter being the dominant? Has some crazy philosophical implications.
You're describing the matter-antimatter asymmetry problem
https://home.cern/science/physics/matter-antimatter-asymmetry-problem
I mean if you just thought of all those questions on your own, that's damned impressive. You just summarized one of the greatest mysteries in particle physics. Here's a story about that exact question - what was the process that gave preference to creation of matter over antimatter?
https://www.scientificamerican.com/article/why-is-there-more-matter-than-antimatter/
The universe very nearly did cancel itself out entirely. That’s why it is as empty as it is. The matter you see is the slight surplus there wasn’t enough antimatter to annihilate. Why this surplus? It’s one of the great remaining problems.
I think there’s an extreme form of the anthropogenic principle we can apply here. Universes may pop into existence constantly and destabilize into nothing because their physical laws aren’t fine tuned for stability, or because they don’t have an uneven amount of anti/matter. Perhaps universes are part of some extra-cosmic superstructure that’s just frothing like mad. Some bubbles last a little longer than others before they pop. We could be one of those. Perhaps the multiverse is a little bit of suds in some leviathan child’s bathtub.
Oh snap, you know this is a good point. What if the reason lies in other universes? Didn't we detect a possible fingerprint of a collision with another universe In the cosmic heat map looking thing? What if we had a collision at just the right time that caused the destruction of just enough anti-matter to throw off the balance.
If I understand it correctly, annihilation is a 100% efficient process that converts all the matter into energy. After the process is complete there is no matter left over and only energy in the form of light, heat, and other energy forms that go way over my head remains.
Annihilation means exactly that - both particles destroy each other on contact, releasing the energy that composed them.
For the simple case of electron-positron annihilation, they transform into high-energy photons, whose total energy is equal to the total mass-energy of the electron and positron. See: https://en.wikipedia.org/wiki/Electron%E2%80%93positron_annihilation
While atoms can be comprised of antimatter the interactions are generally on a subatomic level, i.e. electron/positron, and proton/antiproton. Since particles/antiparticles are identical to their counterparts aside from charge any such interactions are total with nothing left over other than the resulting energy release usually in the form of photons. The results of an atom reacting with an anti-atom could have a variety of results depending on the differences in weight between the two. Exactly what those results might be is a bit beyond my lay-understanding of the process.
Isn’t “falling up” just another way of saying that it’s repelled by matter?
Yes