In my limited understanding, antimatter just means the particles have the opposite charge of normal matter. All other attributes are not part of the definition of antimatter.

[–] Bipta@kbin.social -2 points 1 year ago (8 children)

Charge isn't the right word, although I'm not sure what the right word is. Otherwise you've got it right.

[–] LanternEverywhere@kbin.social 33 points 1 year ago (7 children)

No, charge is the right word. But i was wrong about charge being the only difference, apparently antimatter's "parity" and "time" are also opposite of normal matter. Whatever that means.

https://en.m.wikipedia.org/wiki/Antimatter

[–] magoosh@feddit.nl 16 points 1 year ago

The word is charge-parity. All physical systems (at least I'm quantum physics, I cant speak for other fields) are symmetric (nothing changes) if you change C(harge), P(arity) and T(ime reversal) at the same time. This is called CPT symmetry, see https://en.m.wikipedia.org/wiki/CPT_symmetry

As antimatter can be described as normal matter going back in time (see the other comment), it means antimatter can also be described as normal matter transformed under the C and P operators. If T(particle) = antiparticle and CPT(particle) = particle then CP(particle) = antiparticle also.

And the reason you can reverse time is because most of the equations are quadratic: they have a positive and negative solution, one describes particles moving forward in time, the other solution describes antiparticles going backward in time.

NB: in quantum field theory it gets slightly more complicated, lets leave that as homework ;)

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