Timeline of cosmological theories

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. [ citation needed ] The firmament, Sheol and tehom are depicted.
Geocentric celestial spheres; Peter Apian's Cosmographia (Antwerp, 1539)
Naboth 's representation of Martianus Capella's geo-heliocentric astronomical model (1573)
Andreas Cellarius 's illustration of the Copernican system, from the Harmonia Macrocosmica
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.
The earliest known photograph of the Great Andromeda "Nebula" (with M110 to upper left), by Isaac Roberts , 1899.
Three steps to the Hubble constant [ 93 ]
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).
Cosmic microwave background as measured by the Cosmic Background Imager experiment.