Can someone please explain this to me!

[JackDaniels]

I know that the total energy of the universe is 0 and the universe is flat and that means it could have started from nothing but where I get confused is at the very beginning there were sub atomic particles which pop in and out of existence and so does empty space between quarks, then quantum fluctuations happened, and through E=Mc2 energy converted into matter and expansion started.
Can you help explain this and clear it up to me because I am really confused. I don't even know if what I listed above is right.
Thanks.

[Helius]

Well, from what I understand, all this is theoretical physics. Some Theoretical scientist like Lawrence Krauss argue a zero energy universe because, as he explained in his lecture, it is the most mathematically elegant model. However, there is still no way to test this hypothesis, as far as I know. For more information: http://en.wikipedia.org/wiki/Zero-energy_universe
I would say, if you're in college or live near a college, go talk to a professor. From my own experience, they love to talk about this topic.