The universe is commonly defined as the totality of existence, including planets, stars, galaxies, the contents of intergalactic space, and all matter and energy. Definitions and usage vary and similar terms include the cosmos, the world and nature.
Scientific observation of earlier stages in the development of the universe, which can be seen at great distances, suggests that the universe has been governed by the same physical laws and constants throughout most of its extent and history. The universe is believed to be at least 93 billion light years in diameter and has existed for about 13.7 billion years, since it was created by the Big Bang.
There are various multiverse hypotheses, in which physicists have suggested that the universe might be one among many universes that likewise exist. The farthest distance that it is theoretically possible for humans to see is described as the observable universe. Observations have shown that the universe appears to be expanding at an accelerating rate, and a number of models have arisen to predict its ultimate fate.
Read more about Universe: Etymology, Synonyms and Definitions, Size, Age, Contents, Structure, and Laws, Historical Models, Theoretical Models, Shape of The Universe
Famous quotes containing the word universe:
“The universe seems to me infinitely strange and foreign. At such a moment I gaze upon it with a mixture of anguish and euphoria; separate from the universe, as though placed at a certain distance outside it; I look and I see pictures, creatures that move in a kind of timeless time and spaceless space, emitting sounds that are a kind of language I no longer understand or ever register.”
—Eugène Ionesco (b. 1912)
“There are certain queer times and occasions in this strange mixed affair we call life when a man takes this whole universe for a vast practical joke, though the wit thereof he but dimly discerns, and more than suspects that the joke is at nobody’s expense but his own.”
—Herman Melville (1819–1891)
“It would be a poor thing to be an atom in a universe without physicists, and physicists are made of atoms. A physicist is an atom’s way of knowing about atoms.”
—George Wald (b. 1906)