AST-661beginner

The Big Bang Model: Foundations

The Big Bang model describes an early universe that was hotter, denser, and more uniform than today and has expanded and cooled over cosmic time. The Big Bang framework connects particle physics, nucleosynthesis, recombination, structure formation, cosmic age, and the thermal history of the universe.

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The Big Bang Model: Foundations

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Prerequisites

AST-660Expansion of the Universe & the Hubble–Lemaître Law: Advanced Connections→

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AST-662The Big Bang Model: Structures & Vocabulary→

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The Big Bang model describes an early universe that was hotter, denser, and more uniform than today and has expanded and cooled over cosmic time.

supported

Running cosmic expansion backward implies increasing density and temperature.

supported

The CMB has an almost perfect thermal spectrum, observed helium and deuterium abundances agree with early-universe nuclear calculations, and galaxy redshifts demonstrate expansion.