Universe is all of space and time and its contents, which includes planets, moons, minor the contents of intergalactic space and all matter and energy. The size of the entire Universe is still unknown.
The Big Bang theory:
The Big Bang theory is the prevailing cosmological description of the development of the Universe.
The spacetime fo the Universe is usually interpreted form Euclidean perspective, with space as consisting of three domension, the "fourth domension."
The size of the Universe is somewhat difficult to define.
Dark Energy:
An explanation for why the expansion of the Universe is accelerating remains elusive. It is often attributed to "dark energy".
Mythologies:
Many cultures have stories describing the origin of the world and universe. Cultures generally regard these stories as having some truth.
