From: "Doug Pensinger"
>
> 2) I'm not a proponent of the steady state theory, so please don't
interpret
> this question as such, I just want to juxtapose stuff that I've read. One
of
> the arguments against the steady state idea is the problem of entropy, but
> doesn't the BB violate conservation of matter? Where did all this stuff
come
> from? I read something Hawking wrote to the effect that matter came from
> energy and that energy came from gravity, but where did the gravity come
> from?
>
It's possible for the net energy of the universe to be zero. Objects in
gravitational fields have negative energy, which can cancel out the positive
mass-energy of the objects themselves. This can't happen for normal
objects, because they'd collapse into a black hole first, but it can happen
for the universe as a whole, if it has the right curvature.
Also, if before then Planck time the metric didn't exist, then we wouldn't
expect energy to be conserved, locally or globally. Energy wouldn't be
a meaningful concept in those conditions.
