>>12814787The universe, for the purposes of science, is the visible universe, as anything else is excluded by positivism. It's a sphere with us at the center, with a wall at 13.7 billion light-years away (as measured by defining "now" along a light-ray starting on the earth, going out in a backwards-oriented cone), at which the big-bang can be thought of as still banging, and this wall is like a black hole horizon, and which is flying outward at slightly less than the speed of light, and which will slow down more at some point in the future when dark-energy dominates, and then stop and just sit there, sucking everything away from us until the whole observable universe is a horizon surrounded almost empty de-Sitter space (just us and some neighboring galaxies) with a cosmological horizon spherical wall at a radius of something like 70 bn. lightyears.
That's it. That's the universe. Everything else is unwarranted extrapolation using models which are of dubious validity outside the cosmological horizon, and the extrapolations are not necessary, since they do not affect observations directly.
The shape of the universe is spherical around any observer, so we are not in a special place. This is a little counterintuitive.
