Juicio Oral

The Universe is commonly defined as the totality of everything that exists,[1] including all physical matter and energy, the planets, stars, galaxies, and the contents ofintergalactic space[2][3], although this usage may differ with the context (see definitions, below). The term Universe may be used in slightly different contextual senses, denoting suchconcepts as the cosmos, the world, or nature.
Observations of earlier stages in the development of the universe, which can be seen at great distances, suggest that the Universe hasbeen governed by the same physical laws and constants throughout most of its extent and history.

History

Throughout recorded history, several cosmologies and cosmogonies havebeen proposed to account for observations of the Universe. The earliest quantitative geocentric models were developed by the ancient Greeks, who proposed that the Universe possessesinfinite space and has existed eternally, but contains a single set of concentric spheres of finite size – corresponding to the fixed stars, the Sun and various planets – rotatingabout a spherical but unmoving Earth. Over the centuries, more precise observations and improved theories of gravity led to Copernicus's heliocentric model and the Newtonian model ofthe Solar System, respectively. Further improvements in astronomy led to the realization that the Solar System is embedded in a galaxy composed of millions of stars, the Milky Way,and that other galaxies exist outside it, as far as astronomical instruments can reach. Careful studies of the distribution of these galaxies and their spectral lines have led tomuch of modern cosmology. Discovery of the red shift and cosmic microwave background radiation revealed that the Universe is expanding and apparently had a beginning.
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