Antimatter's RoleThe Universe's Matter-Antimatter ImbalanceFrom a cosmological point of view, we exist because of a matter-antimatter imbalance. Matter and antimatter behave in similar ways, but they exist in very different quantities: matter surrounds us, while antimatter is nonexistent except for fleeting moments when it is produced in collisions before annihilating away. What is the difference between them? It's a question that puzzled physicists for decades. We say that ordinary matter is made up of particles and antimatter is made up of antiparticles. What, then, is the difference betweenparticles and antiparticles? Physicists have determined that particles and antiparticles are almost the same, except that their quantum numbers are flipped. Matter and antimatter are antitheses. A meeting between matter and antimatter causes them to cancel each other out in an explosive process called annihilation. Any antimatter that shows up in our universe, as far as scientists can tell, annihilates with the matter that inevitably surrounds it. The creation of matter and antimatter happened with the Big Bang: prevailing theories suggest that the Big Bang created equal amounts matter and antimatter. There is an obvious problem with this theory: in that case, all matter and antimatter would have annihilated each other into oblivion. If that happened, our universe would be a rather empty place. So what actually happened? Something after the Big Bang caused matter to dominate over antimatter in our universe. We just need to figure out what it was and how it worked. To do this, we turn to neutrinos, CP Violations and the DAEδALUS experiment. 
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