Previous question: Atheists, what was the origin of all matter of the universe?
Since you blocked me I can't answer, but the origin of matter is the result of energy particle collisions in the early universe. Not only is this known, but it can be demonstrated in any particle collider. Not a mystery in any way.
@Nigel: Yes particle collisions. Energy can exist in a particle form. For example, light is made up of particles called photons. Under the right conditions, high energy collisions can create matter. As I already said, we do this regularly in particle colliders.
@Yossarian: Neat book, but he's wrong. Quantum fluctuations require negative energy provided by gravitational fields. No universe = no spacetime or mass. No spacetime or mass = no gravity. No gravity = no quantum fluctuations. Sadly, the origin of the singularity and what caused it to expand are still a mystery.
@Someone who cares: Not entirely true. Although, as I mentioned above, quantum fluctuations are ruled out of being the origin of the singularity in the big bang, they can indeed create matter from nothing.
@NDMA: We do not yet know the origin of the singularity or what caused it to expand, but when it did, it produced MASSIVE energy. So much so that collisions at EXTREMELY high velocities was not only possible, but inevitable. By the way, your understanding of what happens in particle colliders is very off. ENERGY particles (not matter) collide and PRODUCE matter under the right conditions. You just need to read more on the subject. You understanding is a basic over-view, not a true understanding.
@NDMA: "Perhaps you should try reading past the cover" -- That's a wrong assertion too. My info above is why he's incorrect. The math of quantum fluctuations shows that there is a slight lean on the phenomenon towards the matter side over the anti matter side. Usually both particles annihilate each other, but the lean towards the matter side allows for some matter to come out intact.
@NDMA: Here, read for yourself:
http://en.wikipedia.org/wiki/Matter_creation