A recent episode of the almost always excellent Radiolab documentary series ended with a brief explanation by Marcelo Gleiser of how puzzling it is that there is any matter at all in the universe. As I understood this explanation, energy can become matter as we know, but any created matter also has to create the corresponding antimatter at the same time. Thus, while after the big bang plenty of matter was created, one would expect it all to have been fairly quickly “cancelled out” as it ran into corresponding antimatter and annihilated itself. Except, as it turns out, there is a tiny imbalance in favour of matter when energy becomes matter. Roughly, for every billion particles of antimatter, 1,000,000,001 particles of matter are created, and the entire universe of matter we have today would appear to be as a result of this tiny “leftover” matter.
It seems to me bizarre that a rule of physics which I normally think of as being mathematical and therefore perfectly balanced should have a tiny “flaw”. And, alarmingly, it appears that science does not yet have an explanation for this! Have I misunderstood the explanation given? What is the name of the law or phenomenon that is being referred to? Is there a layman’s guide to it in more detail out there on the web? Or is the phenomenon itself a scientifically disputed one?