Why is there no antimatter in the Universe?
1 Answer
There would have been antimatter in the early universe.
Explanation:
In the moments after the big bang there would have been equal quantities of matter and antimatter. Antimatter being antiprotons, antineutrons and positrons. The problem with this is that all of the matter and antimatter would have annihilated each other just leaving radiation.
One possibility is that the matter and antimatter somehow got separated and there are antimatter galaxies. The problem with this is that when matter and antimatter meet they annihilate each other producing gamma ray radiation. This means that there can't be nearby antimatter galaxies as we would see the radiation signature of matter and antimatter meeting in intergalactic space.
The other possibility is that matter is favoured over antimatter. As far as we know particles and antiparticles are identical except for having opposite properties such as charge. It is possible that in the conditions soon after the big bang, matter particles were slightly more stable and all of the antimatter was either annihilated or decayed.
As we know for a fact that there is an abundance of matter in the universe, something must have happened to the antimatter. We don't yet know what actually happened to the antimatter.
