Timeline of cosmological theories

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This timeline of cosmological theories and discoveries is a chronological record of the development of humanity's understanding of the cosmos over the last two-plus millennia. Modern cosmological ideas follow the development of the scientific discipline of physical cosmology.


For millennia, what today is known to be the Solar System was regarded as the contents of the "whole universe", so advances in the knowledge of both mostly paralleled. Clear distinction was not made until circa mid-17th century. See Timeline of Solar System astronomy for further details on this side.


Early Hebrew conception of the cosmos.
The firmament, Sheol and tehom are depicted. Early Hebrew Conception of the Universe.svg
Early Hebrew conception of the cosmos. The firmament, Sheol and tehom are depicted.
Geocentric celestial spheres; Peter Apian's Cosmographia (Antwerp, 1539) Ptolemaicsystem-small.png
Geocentric celestial spheres; Peter Apian's Cosmographia (Antwerp, 1539)

Middle Ages

Naboth's representation of Martianus Capella's geo-heliocentric astronomical model (1573) Naboth Capella.JPG
Naboth's representation of Martianus Capella's geo-heliocentric astronomical model (1573)


Andreas Cellarius's illustration of the Copernican system, from the Harmonia Macrocosmica Heliocentric.jpg
Andreas Cellarius's illustration of the Copernican system, from the Harmonia Macrocosmica

Enlightenment to Victorian Era

William Herschel's model of the Milky Way, 1785 Herschel-galaxy.jpg
William Herschel's model of the Milky Way, 1785
One of Andrew Ainslie Common's 1883 photographs of the Orion nebula, the first to show that a long exposure could record stars and nebulae invisible to the human eye. Orion-Nebula A A Common.jpg
One of Andrew Ainslie Common's 1883 photographs of the Orion nebula, the first to show that a long exposure could record stars and nebulae invisible to the human eye.


The earliest known photograph of the Great Andromeda "Nebula" (with M110 to upper left), by Isaac Roberts, 1899. Pic iroberts1.jpg
The earliest known photograph of the Great Andromeda "Nebula" (with M110 to upper left), by Isaac Roberts, 1899.
Three steps to the Hubble constant Three steps to the Hubble constant.jpg
Three steps to the Hubble constant


The Karl G. Jansky Very Large Array, a radio interferometer in New Mexico, United States. USA.NM.VeryLargeArray.02.jpg
The Karl G. Jansky Very Large Array, a radio interferometer in New Mexico, United States.
The sky at energies above 100 MeV observed by the Energetic Gamma Ray Experiment Telescope (EGRET) of the Compton Gamma Ray Observatory (CGRO) satellite (1991-2000). Egret all sky gamma ray map from CGRO spacecraft.png
The sky at energies above 100 MeV observed by the Energetic Gamma Ray Experiment Telescope (EGRET) of the Compton Gamma Ray Observatory (CGRO) satellite (19912000).


Cosmic microwave background as measured by the Cosmic Background Imager experiment. Cosmic Background Imager- CMB.png
Cosmic microwave background as measured by the Cosmic Background Imager experiment.

See also

Physical cosmology

Historical development of hypotheses

Belief systems


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