Galaxies and Cosmology

The scientific model describing the Universe as having expanded from an extremely hot, dense early state about 13.8 billion years ago.

The scientific model describing the origin and early evolution of the Universe from an extremely hot, dense state.

a proposed scenario in which cosmic expansion reverses into contraction.

a scenario in which expansion continues and the Universe becomes increasingly cold and dilute.

a hypothetical scenario involving increasingly extreme accelerated expansion.

the increase in distances between widely separated regions of the Universe as space expands.

Faint microwave radiation left over from the early stages of the Universe, providing strong evidence for the Big Bang model.

(Λ) - a possible explanation for dark energy involving an approximately constant energy density of space.

The scientific study of the origin, structure, evolution, and future of the Universe.

A form of energy thought to be responsible for the accelerating expansion of the Universe.