Antimatter mystery - 02 September 2009 - New Scientist
Experiments in accelerators now tell us that for every 10 billion antiprotons present in the early universe, there were 10-billion-and-one protons. The same tiny imbalance applied to other particles, such as electrons, too. At some point in cosmic history, matter and antimatter met and annihilated. Left behind, those extra particles eventually came together and formed the matter-filled universe we know today. So what created that initial imbalance?
