Cosmology

The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia,[2] and in 1731 taken up in Latin by German philosopher Christian Wolff in Cosmologia Generalis.

Because of this shared scope with philosophy, theories in physical cosmology may include both scientific and non-scientific propositions and may depend upon assumptions that cannot be tested.

Modern physical cosmology is dominated by the Big Bang Theory which attempts to bring together observational astronomy and particle physics;[5][6] more specifically, a standard parameterization of the Big Bang with dark matter and dark energy, known as the Lambda-CDM model.

Theoretical astrophysicist David N. Spergel has described cosmology as a "historical science" because "when we look out in space, we look back in time" due to the finite nature of the speed of light.

[7] Physics and astrophysics have played central roles in shaping our understanding of the universe through scientific observation and experiment.

Greek philosophers Aristarchus of Samos, Aristotle, and Ptolemy proposed different cosmological theories.

It provided a physical mechanism for Kepler's laws and also allowed the anomalies in previous systems, caused by gravitational interaction between the planets, to be resolved.

Modern scientific cosmology is widely considered to have begun in 1917 with Albert Einstein's publication of his final modification of general relativity in the paper "Cosmological Considerations of the General Theory of Relativity"[11] (although this paper was not widely available outside of Germany until the end of World War I).

This difference of ideas came to a climax with the organization of the Great Debate on 26 April 1920 at the meeting of the U.S. National Academy of Sciences in Washington, D.C.

However, this result was later found to be spurious: the supposed evidence of gravitational waves was in fact due to interstellar dust.

Creation myths are found in most religions, and are typically split into five different classifications, based on a system created by Mircea Eliade and his colleague Charles Long.

The Hubble eXtreme Deep Field (XDF) was completed in September 2012 and shows the farthest galaxies ever photographed at that time. Except for the few stars in the foreground (which are bright and easily recognizable because only they have diffraction spikes ), every speck of light in the photo is an individual galaxy, some of them as old as 13.2 billion years; the observable universe is estimated to contain more than 2 trillion galaxies. [ 1 ]
Representation of the observable universe on a logarithmic scale . Distance from the Sun increases from center to edge. Planets and other celestial bodies were enlarged to appreciate their shapes.