Universe
Universe[edit | edit source]
The universe is the totality of space, time, matter, and energy. It encompasses everything that exists, from the smallest subatomic particles to the largest galaxies. The universe is governed by the laws of physics and is constantly expanding.
Origin and Evolution[edit | edit source]
The prevailing cosmological model for the origin of the universe is the Big Bang theory. According to this theory, the universe began approximately 13.8 billion years ago from an extremely hot and dense state and has been expanding ever since. The cosmic microwave background radiation is a remnant of the early universe, providing evidence for the Big Bang.
Structure[edit | edit source]
The universe is composed of galaxies, which are collections of stars, gas, dust, and dark matter. These galaxies are organized into clusters and superclusters, forming a vast cosmic web. The Milky Way is the galaxy that contains our Solar System.
Composition[edit | edit source]
The universe is made up of ordinary matter, dark matter, and dark energy. Ordinary matter includes atoms and molecules, while dark matter is a mysterious substance that does not emit light but exerts gravitational forces. Dark energy is thought to be responsible for the accelerated expansion of the universe.
Theories and Models[edit | edit source]
Several models attempt to describe the universe's structure and behavior. The Standard Model of particle physics explains the fundamental particles and forces, while general relativity describes the gravitational interaction on a cosmic scale. The Lambda-CDM model is the standard model of cosmology, incorporating dark energy and cold dark matter.
Future of the Universe[edit | edit source]
The ultimate fate of the universe is still uncertain. Several scenarios have been proposed, including the Big Freeze, Big Crunch, and Big Rip. These outcomes depend on the properties of dark energy and the overall density of the universe.
Related Pages[edit | edit source]
References[edit | edit source]
- Peebles, P. J. E. (1993). Principles of Physical Cosmology. Princeton University Press.
- Weinberg, S. (2008). Cosmology. Oxford University Press.
Gallery[edit | edit source]
Hubble Ultra Deep Field
Hubble Legacy Field Zoom Out
CMB Timeline
Logarithmic Illustration of the Universe
End of the Universe
Formation of Galactic Clusters
Near-Infrared Sky
Universe Content Bar Chart
Standard Model of Elementary Particles
Aristarchus of Samos
Flammarion Engraving
Thomas Digges' Map
The Earth from Apollo 17
Solar System in True Color
Radcliffe Wave
Milky Way Arms
Artist's Impression of the Milky Way
Local Group and Nearest Galaxies
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