Summations Only

Let's be clear about what is currently known.The current theory of gravity, known as General Relativity, will produce a spacetime for any
given collection of matter. So first of all, what is a spacetime? A spacetime is a four-dimensional shape,
just as a sphere is a two dimensional shape or a cube is a three dimensional shape. However this shape
has time built into it as one of its dimensions, so it behaves a little differently to normal shapes, however
that doesn't really matter for now.What a spacetime describes is an entire history of a universe, the curves and contours in the shape, describe
the paths objects take as they evolve in space and time. As human beings, we see these paths as gravitational
orbits.In what follows _ means a subscript and:
0 = time
1 = x-direction
2 = y-direction
3 = z-directionThe next most important thing is the matter. This is described via an object called the Stress-Energy Tensor,
T_uv (_ means subscript). T_uv looks like a matrix, such as this:T_00 T_01 T_02 T_03
T_10 T_11 T_12 T_13
T_20 T_21 T_22 T_23
T_30 T_31 T_32 T_33T_00 is the density of mass, amount of matter per volumeT_10, T_20, T_30, are momentum per unit volumeT_11, T_22, T_33, are pressureT_21, T_31, T_32, T_23, T_13, T_12, are shear stress. The kind of stress that rips things, or
the kind of stress that occurs when things rub off or flow over each other.T_01 T_02 T_03, are energy flux, for example heat conduction, the transfer of energy basically.G_uv is a geometric object, that tells you about the curvature of a spacetime. Basically you
take an arrow pointing in any direction. For example an arrow pointing in the y-direction:^
|then drag it along a square, with one side along the u direction and the other along the
y-direction. So for G_12, I'll drag the arrow along x and y directions.First I drag it along the x-direction:
↑↑↑↑↑↑↑↑then the y-direction:
↑
↑
↑
↑↑↑↑↑↑↑↑Then back along the x direction:
↑↑↑↑↑↑↑↑
↑
↑
↑↑↑↑↑↑↑↑and back down along the y-direction to complete the square.In a flat space, the arrow will align perfectly with how it started.
In a curved space it won't, so this provides a measure of the curvature. G_12 is basically the difference or "gap" between arrow after it travels around the square and its original position.
(An example is to be found here, for a sphere:The Riemann Curvature Tensor , just scroll down to the picture of a sphere and you'll see a vector being dragged along.)G_uv is this process for all squares you could try, a z/y-square for example.General Relativity says the following:G_uv = 8pi T_uv.So the change in the arrow is proportional to the amount numbers I gave at the beginning. For example, taking u = 1 and v = 2:G_12 = 8pi T_12so in a spacetime, the change in the arrow after being dragged along the square I've described above is given by the amount of shear
stress times 8pi. Specifically the shear stress coming from an object with momentum in the x-direction pushing against a plane of
material lying in the y-direction.So the mass density, shear stress, momentum density and energy flux (e.g. heat flow) completely determine the curvature of the spacetime.
If you know the curvature, you know the spacetime, so you have then figured out the spacetime.So, when we look at the night sky we see a roughly homogeneous cloud of gas on the largest scales. Of course it doesn't look like that to us,
but on the largest scales that is what the universe looks like. So, we write down the T_uv matrix of a cloud of homogenous cloud of gas. Quite
easy because a cloud of gas has no shear stress, so a lot of the terms are just zero. Then we use Einstein's equations to figure out the curvature.
The result is a spacetime which gets smaller in space as you turn back time. The "Big Bang" spacetime, because when played forward, its early sections
look like an explosion. When we apply this spacetime to our universe, with its particular collection of matter, it turns out the universe would have been
about the size of a tennis ball about 13.7 billion years ago. Unfortunately we can't go any further back than this because the equation:G_uv = 8pi T_uvbecomes unreliable.So that's it. I don't particularly see anything there that implies a creator god.Edited by Son Goku, : No reason given.

I should have said I mean a sphere the way it is talked about in mathematics, i.e. the surface
of a ball, not the whole ball. This is a two-dimensional curved object.

This is not correct. In the standard cosmology, the universe has period about 13.7 billion years ago that would look like an explosion to a human being. At the earliest parts of this period, the universe is very small. What happened before that is unknown.

I'll try something a bit different, it might be stupid, but anyway....As we all know the Roman Empire expanded over history, there are some periods of rapid expansion (conquest of Gaul and Britain) and slower ones (Iberia). Played in reverse we see the empire slowly shrink in size until it contracts to the hilly region around the Seven Hills of Rome.Now one could continue this extrapolation until Rome contracts to a single point of infinite Roman density on the Capitoline hill, which must have been Romulus and Remus, the semi-devine beings of myth.Or maybe the social dynamics change and you shouldn't apply the expansion rules of an empire to a small Iron Age settlement.

No. My disagreement is with the use of the Big Bang as the beginning of the universe. The theory only says the universe was very small about 13.7 billion years ago, prior to that point "something else" occurs and it is invalid to continue to use the equations. If you do you get the fictitious singularity, but that's not meaningful.The Big Bang theory tells how the universe has evolved over the past 13.7 billion years from a hot dense ball (but not a singularity). What existed prior to that hot little ball is unknown.