What does cosmology mean?
Cosmology is the branch of science concerned with the universe as a whole: its origins, its large-scale structure, and its evolution through time. As a modern scientific discipline it draws on physics and astronomy, using observations of distant light, radiation, and matter to build theories about events such as the Big Bang, the expansion of space, and the formation of galaxies. The word is also used more broadly to mean any systematic account or theory of the cosmos, including those offered by religions, mythologies, and philosophical traditions, which describe the world in terms that are not strictly scientific. Cosmology is therefore both a technical term and a word for humanity's deepest attempts to situate itself within the whole of existence. It carries a formal, intellectual connotation and appears chiefly in academic and popular-science writing, though interest in it extends well beyond specialists, since its questions — where the universe came from, what it is made of, and how it will end — are among the oldest humans have asked.
The scientific study of the origin, evolution, and large-scale structure of the universe.
"Her research in cosmology focuses on dark energy and the accelerating expansion of the universe."
Often qualified by adjectives such as 'modern', 'observational', or 'theoretical'.
A specific theory, system, or account of the nature and structure of the cosmos, whether scientific, philosophical, or mythological.
"Ancient Egyptian cosmology placed the earth at the centre of a divinely ordered sky."
Used mainly when referring to multiple distinct systems or accounts of the cosmos (e.g., different cultural or historical cosmologies), rather than to repetitions of the science itself.
"Comparing the creation narratives of several traditional cosmologies reveals striking structural similarities."
Cosmology is one of the few sciences in which the entire subject of study — everything that exists — is a single object of inquiry.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cosmology
Cosmology derives from the Greek words kosmos, meaning 'order' or 'world', and logia, meaning 'study' or 'account'. The term entered English in the 17th century, when scholars began applying systematic natural philosophy to questions about the heavens. Its cognates share the same Greek root: words such as cosmos, cosmopolitan, and microcosm all reflect the ancient Greek sense of an ordered, structured universe.
Related word forms
How cosmology is actually used
Formal register; primarily used in academic, scientific, and philosophical writing. In everyday use it may appear loosely to mean any worldview or picture of the cosmos.
Easily confused with cosmology
Cosmogony concerns the origin of the universe specifically, while cosmology covers the universe's overall structure and evolution as well as its origins.
Astrology is the pseudoscientific practice of divining human affairs from celestial bodies, whereas cosmology is a rigorous branch of science.
Astronomy studies individual celestial objects such as stars and galaxies, while cosmology studies the universe as an integrated whole.