The "old school" Greek classical philosopher Plato and his student Aristotle, left us with the gem described in the question. The theory (geocentric model) was passed along, and a couple of centuries after them, Ptolemy wrote in support of the idea. The model persisted for something on the order of 1400 years. Talk about man's ego! A link is provided.
Yes, the moon is almost perfectly spherical - almost. <><><><><> Its actually spheroidal - like nearly all of the suns, planets and moons in the Solar System, even possibly in the entire Universe, because they rotate, and that causes an spheroidal shape as they cool.
Since all of the planets, and moons, and stars seem to have a spherical shape, it is possible that the universe may be a sphere.
Einstein
Nobody knows. They do not even know if it is finite or infinite.
gas
My universe is composed of a complex mixture of matter, energy, space, and time, along with information.
Atoms on mars are composed of protons and electrons which are composed of quarks, the same as atoms everywhere in the universe.
everything we see in the universe
He is the father of spherical astronomy, by which the location of objects like planets and stars in the universe can be determined.
The Universe
This is called "reality".
aristotle and nicolaus copernicus