From forming bound states to normal scattering, many possibilities abound for matter-antimatter interactions. So why do they annihilate?
From forming bound states to normal scattering, many possibilities abound for matter-antimatter interactions. So why do they annihilate? There’s a quantum reason we simply can’t avoid.
I don't see that the article actually answers the question. It mostly talks about what happens if/when particles and antiparticles interact, not why annihilation happens.
I'm a smoothbrain, so I like to think about it as them simply canceling each other out. What I'm more curious about though, is why there's so much matter compared to antimatter.
You’re not alone; matter-antimatter asymmetry is one of the big open questions in physics. Most particle processes treat matter and antimatter identically, but there are a few areas where matter and antimatter have slightly different interactions. These occurrences are violations of Charge Parity symmetry aka CP Violation.
There must have been a certain amount of CP violation during the early phases of the Big Bang to explain our matter-dominated universe. But the known amounts of CP Violation are nowhere near enough to explain the asymmetry in matter and antimatter. There are some proposed mechanisms that would violate CP symmetry in sufficient quantities, but these haven’t been experimentally observed. There are ongoing searches to detect these processes, or related processes that would be possible if these existed. Neutrinoless double beta decay searches are one example of these detection efforts.
In summary, there’s a guaranteed Nobel Prize to whoever can answer your question.
I work on a 0nuBB search doing detector R&D, this is spot on, but has 2 extra components. The three elements needed for explaining the asymmetry are:
CP Violation
Lepton or Baryon Number violation
Interactions out of thermal equilibrium
These are the Sakharov conditions for Baryogenesis/Leptogenesis. #1 has been observed via the weak interaction but not in large enough quantities and is not observed via strong interactions, #2 is what proton decay and 0nuBB searches look for, and #3 can be, at least partially, explained by the expansion of the universe as a non-equilibrium interaction.
To get from leptogenesis to baryogenesis requires theretical physics I only barely understand using particles call sphaelerons that convert leptons to baryons.
Part of me is still half-convinced that there are whole galaxy clusters of antimatter that are simply too far away from other clusters to produce any noticeable gamma rays, and the reason they didn't interact near the beginning of the universe is the same reason the whole thing didn't collapse into a super massive black hole: we don't know yet, but probably along the same lines as dark energy. A lot of it did probably interact though and that's where a lot of the CMB comes from.
I'm definitely a lay person though, I'm sure an actual physicist can tell me that's definitely not the case, I just don't know why not yet.
annihilation results in a large energy release. so nothing is actually disappearing. changing form maybe. I'm guessing at the big bang matter/anti-matter went opposite directions and we just can't see that half. not speculating about symmetry. just a large amount of anti-matter beyond observational light-speed limits. speculation
If we could figure out how to use it to make sustainable reactors, we could probably produce a fuckton of energy? It can help us better understand our universe and advance science?