Summary

The Big Bang should have been the start and the end of the Universe, as we understand it. In many ways, the cosmos likes balance, so it's thought the Big Bang should have made matter and antimatter in equal amounts, leading them to destroy each other and leave only space and energy. But an infinitesimal imbalance existed at some point in the early Universe that allowed matter to exist, which is important because humans and other stuff tend to be made of matter.

AI summaries can be wrong sometimes—always verify important details using the source article.