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:
“So Sam enters the universe of sleep, a man who seeks to live in such a way as to avoid pain, and succeeds merely in avoiding pleasure. What a dreary compromise is life!”
—Norman Mailer (b. 1923)
“Some people swallow the universe like a pill; they travel on through the world, like smiling images pushed from behind.”
—Robert Louis Stevenson (1850–1894)
“The universe constantly and obediently answers to our conceptions; whether we travel fast or slow, the track is laid for us. Let us spend our lives in conceiving then. The poet or the artist never yet had so fair and noble a design but some of his posterity at least could accomplish it.”
—Henry David Thoreau (1817–1862)