: With present theory, all matter was created in a few instants in the "begining". What emerged from the Higgs field after the cooling occured (in much less than one second) were the quarks, which subsequently condensed into protons and neutrons, and finally into protons and electrons. Which in turn condensed into hydrogen. Due to gravitational attraction, the hydrogen massed in a universe with similar properties to the one we are familiar with. This hydrogen underwent fusion, and then its products fused and so on, and thus the plethora of present day elements was created. However, this is a one way street. Because of the binding energies of nuclei, atoms lighter than iron tend to fuse, like hydrogen ..., and atoms heavier than iron, like uranium, tend to fission. In otherwords, things tend towards their lowest energy state, and this means no new hydrogen will be produced. In other words, the stars will become extinct one day. Eventually the universe will suffer a "heat death" do to the minimization of the free energy (free energy=energy+temp*entropy) when this happens, there will be no driving force, and the universe will remain stagnant. Kind of depressing.

: This, of course, assumes that the universe is not closed. The "heat death," as I understand it, would take an unimaginably long time (long enough to not only watch the stars grow perpetually cold but also to the point where event he balck holes themselves have dissipated (isn't the time scale something like 10e64 years?). Anyway, the universe might just collapse back to a single point, space and all, which may well be different from the usual garden-variety black hole, and then we need to come up with a different long-term characterization.