Why is there matter when all of it should have annihilated with antimatter? The theory is that after the Big Bang, photons turned into matter and antimatter particle pairs, but they should have all annihilated with each other. Since there would be an equal amount of matter and antimatter created due to conservation principles? Or is the leftover matter a sort of consequence of infinite series summation like how $1+2+3+4+...=-\frac{1}{12}$? Similarly, is the answer to an infinite series of matter/antimatter annihilation:$ 1-1+2-2+3-3+...$ the amount of matter that is leftover since it's not necessarily zero? So most of the matter would have annihilated, but there was a finite sum left over?
Basically, my question is if the leftover matter that should have annihilated due to conservation but didn't merely a result of the fact that infinite series summation is not necessarily zero?
 A: This is one of the big unsolved questions in physics. If you can figure out the answer and convince the physics community it's correct, you'll probably win a Nobel prize.
A: If only it were as simple as there being some quirk in the math when subtracting infinities. Unfortunately (but fascinatingly), we don't know the real answer to this. What appears to have happened is that slightly more matter particles were produced than antimatter particles, with the extra matter going on to form the universe which we see today.
But why was more matter produced than antimatter? We think that it had to do with the fact that the laws of physics are not exactly the same when one substitutes antimatter for matter or vice versa. This is called C-symmetry violation and has been experimentally confirmed to be true (specifically regarding the "weak interaction"). But we still don't know exactly what happened.
A: In the context of the Rishon model (of which we can not yet say if it's true though; higher collision energies are needed in particle accelerators) this question can be easily answered.
According to this theory, there are equal amounts of matter and anti-matter in our Universe. Also, according to this theory, there are only two (more economical it can't get!) truly elementary particles out of which all quarks and leptons are composed:
$T$-rishons, with an electric charge of $\frac 1 3$, a unit of charge corresponding to the strong force, and a unit charge associated with a new kind of color force (much stronger than the normal color force), called the hyper color force.
$V$-rishons, with zero electric charge, a unit of charge corresponding to the strong force, and a unit of anti-charge corresponding to this new hyper color force.
All quarks and leptons are composed out of three of these rishons. To name a few examples:
The up-quark (containing $\frac 2 3$ of electric charge) contains two $T$-rishons and one $V$-rishon: $TTV$. All its family members (the charm-quark and the bottom-quark) are seen as an excitation of this $TTV$ combination.
The electron contains three anti-$T$-rishons: $\bar T\bar T\bar T$. Its family members (the muon and the tau) are, just as in the quark example, excitations of this $\bar T\bar T\bar T$ combination.
You can easily figure out which rishons the neutrinos are composed of. Now it seems to me that it's reasonable to assume that there exists another Universe where all the quarks and leptons we know to exist, are the anti-particles of those in our own Universe. So a proton here is an anti-proton "out there", a neutron an anti-neutron, an electron a positron, or a neutrino an anti-neutrino. This gives a nice symmetrical touch to the story.
Future experiments (if Nature hasn't come to an end yet) can look for this sub structure of quarks.
