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Glossary term: Cosmological Principle

Description: The cosmological principle is the basis for modern cosmology and is built on observations and a fundamental assumption. It states that spatially the Universe is isotropic and homogeneous on large scales (clusters of galaxies). Observations on sufficiently large scales, show that the Universe appears to "look" the same in any direction; there is no preferred direction (isotropic). The fundamental assumption, based on the Copernican Principle (humans do not occupy a special location in the Universe), is that the Universe is the same everywhere (homogeneous); there appears to be no preferred location. The cosmological principle is accompanied by universality, where the laws of physics and the fundamental constants are the same everywhere in the Universe, here on Earth or a distant galaxy.

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Term and definition status: This term and its definition is still awaiting approval

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".