The term Universe has a variety of meanings based on the context in which it is described. In philosophical terms, the Universe is the summation of all that exists and the space in which all events occur. In cosmological terms, the Universe is thought to be a finite or infinite space-time continuum in which all matter and energy exist. (It has been hypothesized by scientists that the Universe is part of a system of many other universes, known as the multiverse.) The terms known Universe, observable Universe, or visibl ...

Including:

• Universe - Expansion and age and the Big Bang theory
• Universe - Size of Universe and observable Universe
• Universe - Shape of the Universe
• Universe - Fate of the Universe
• Universe - Multiverse
• Universe - Other terms

Read more here: » Universe: Encyclopedia - Universe

An important open question of cosmology is the shape of the Universe. Mathematically, which 3-manifold represents best the spatial part of the Universe? Firstly, whether the Universe is spatially flat, i.e. whether the rules of Euclidean geometry are valid on the largest scales, is unknown. Currently, most cosmologists believe that the observable Universe is very nearly spatially flat, with local wrinkles where massive objects distort spacetime, just a ...

See also:

Universe, Universe - Expansion and age and the Big Bang theory, Universe - Size of Universe and observable Universe, Universe - Shape of the Universe, Universe - Fate of the Universe, Universe - Multiverse, Universe - Other terms

Read more here: » Universe: Encyclopedia II - Universe - Shape of the Universe

The most important result of cosmology, the understanding that the Universe is expanding, is derived from redshift observations and quantified by Hubble's Law. Extrapolating this expansion back in time, one approaches a gravitational singularity, a rather abstract mathematical concept, which may or may not correspond to reality. This gives rise to the Big Bang theory, the dominant model in cosmology today. The age of the Universe from the time of the Big Bang, was estimated to be about 13.7 billion (13.7 × 109) years, with a marg ...

See also:

Universe, Universe - Expansion and age and the Big Bang theory, Universe - Size of Universe and observable Universe, Universe - Shape of the Universe, Universe - Fate of the Universe, Universe - Multiverse, Universe - Other terms

Read more here: » Universe: Encyclopedia II - Universe - Expansion and age and the Big Bang theory

Different words have been used throughout history to denote "all of space", including the equivalents and variants in various languages of "heavens", "cosmos", and "world". Macrocosm has also been used to this effect, although it is more specifically defined as a system that reflects in large scale one, some, or all of its component systems or parts. (Similarly, a microcosm is system that reflects in small scale a mu ...

See also:

Universe, Universe - Expansion and age and the Big Bang theory, Universe - Size of Universe and observable Universe, Universe - Shape of the Universe, Universe - Fate of the Universe, Universe - Multiverse, Universe - Other terms

Read more here: » Universe: Encyclopedia II - Universe - Other terms