Cosmogony

Cosmogony, from the Greek kosmos (order) and gonia (birth), is the study of the origin of the cosmos. In mythology, it refers to creation stories that explain how the universe and life began, often involving deities or primordial forces. In science, cosmogony overlaps with cosmology but focuses on the formation of specific structures—such as stars, planets, and galaxies—rather than the universe as a whole.¹ The term is sometimes used interchangeably with cosmology, but cosmogony is more concerned with the processes and events that led to the present state.

Mythological cosmogonies are among the oldest recorded human thoughts. The Babylonian Enuma Elish (c. 12th century BCE) describes the universe emerging from a primordial watery abyss, with the god Marduk creating the heavens and Earth from the body of the sea goddess Tiamat.² Hesiod's Theogony (c. 700 BCE) presents a Greek cosmogony where Chaos gives rise to Gaia (Earth) and other primordial deities. In many traditions, creation is depicted as a cosmic egg, a world tree, or a divine utterance, reflecting diverse cultural metaphors for order emerging from chaos.

Scientific cosmogony began with the realization that the universe has a history. The modern Big Bang theory, supported by the cosmic microwave background and the expansion of galaxies, describes the universe's origin from a hot, dense state about 13.8 billion years ago.³ However, cosmogony also addresses the formation of the Solar System: the nebular hypothesis, first proposed by Immanuel Kant and Pierre-Simon Laplace, holds that the Sun and planets formed from a rotating cloud of gas and dust. This model has been refined with observations of protoplanetary disks around young stars.

Beyond the mainstream, cosmogony includes niche theories and figures. The ancient Greek philosopher Anaximander proposed an early scientific cosmogony where the universe arises from the apeiron (the boundless). In the 18th century, the Swedish scientist Emanuel Swedenborg anticipated the nebular hypothesis in his 1734 work Principia. In modern physics, the concept of cosmic inflation, proposed by Alan Guth in 1980, addresses the universe's uniformity, but its details remain speculative. Additionally, the study of exoplanet systems has revealed that planetary formation can occur in diverse environments, challenging earlier assumptions.

While cosmogony and cosmology are often conflated, they differ in focus. Cosmology is the study of the universe as a whole—its structure, evolution, and ultimate fate—whereas cosmogony is concerned with the origin of its components. For example, stellar cosmogony investigates how stars form from molecular clouds, while planetary cosmogony examines the accretion of planets from protoplanetary disks.⁴ This distinction is crucial in fields like astrophysics, where researchers study the birth of galaxies and black holes.

Big Bang

The prevailing cosmological model describing the universe's origin from a hot, dense state.

Nebular hypothesis

The theory that the Solar System formed from a rotating cloud of gas and dust.

Cosmic microwave background

The thermal radiation left over from the Big Bang, discovered in 1965.

Inflation

A hypothesized exponential expansion of the universe in its first moments.