The Origin and Evolution of the Earth

Big Bang Theory

The most accepted theory regarding the origin of the universe, suggesting that all matter existed in a tiny, extremely hot singularity that expanded rapidly about 13.7 billion years ago.

Nebular Hypothesis

Proposed by Laplace, it suggests that the planets were formed from a rotating cloud of gas and dust called a nebula associated with the sun.

Planetesimal Hypothesis

A theory suggesting that a passing star drew out material from the primitive sun, which later condensed into smaller solid bodies called planetesimals that eventually joined to form planets.

Differentiation

The process during the earth's early formation where heavier materials like iron sank toward the center to form the core, while lighter materials rose to the surface to form the crust.

Outgassing

The process through which gases trapped in the earth's interior were released through volcanic eruptions, playing a major role in the evolution of the early atmosphere.