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:
“There are acacias, a graceful species amusingly devitalized by sentimentality, this kind drooping its leaves with the grace of a young widow bowed in controllable grief, this one obscuring them with a smooth silver as of placid tears. They please, like the minor French novelists of the eighteenth century, by suggesting a universe in which nothing cuts deep.”
—Rebecca West (1892–1983)
“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)
“What the hell is nostalgia doing in a science-fiction film? With the whole universe and all the future to play in, Lucas took his marvelous toys and crawled under the fringed cloth on the parlor table, back into a nice safe hideyhole, along with Flash Gordon and the Cowardly Lion and Luck Skywalker and the Flying Aces and the Hitler Jugend. If there’s a message there, I don’t think I want to hear it.”
—Ursula K. Le Guin (b. 1929)