(February 23, 2018 at 6:16 pm)Banned Wrote: If you buy into the idea of the expanding universe, you could ask if the expansion is due to gravity on it's outer limits.
Didn't the BB create space time, and the supposed curvatures of it that cause gravity?
If the outer edge of the universe is the border of space time, it would contain the beginning properties of the BB, which could mimic a space time condition that's great enough to cause the expansion.
Since space time is supposedly created by the BB, the expansion of the universe may not be dependent on gravity at all, but on the properties which caused the BB in the first place.
In the standard BB description, there are no 'outer limits'. The universe is always spatially homogeneous: the same in all directions. Even if space is finite in extent, there are no boundaries in the way you seem to be asking.
