Big History: Emergence of Complexity in the Early Universe

Vocabulary flashcards covering key Big History concepts from the notes, including thresholds, Goldilocks conditions, the early universe, matter formation, gravity-driven structure formation, and the relationship between complexity and fragility.

Threshold

A point in cosmic development where achieving higher complexity becomes harder, requiring tighter Goldilocks conditions.

Goldilocks conditions

The just-right set of conditions that allow new, more complex structures to emerge; not too hot or too cold, not too diffuse.

Big History

An interdisciplinary narrative that surveys the entire history of the universe to explain the emergence of complexity and its fragility.

Beginning of time (13.7 billion years ago)

The origin point of the universe when time and space began and the cosmic timeline starts.

First second

The early moment after the Big Bang when energy differentiates into distinct forces (including electromagnetism and gravity) and matter forms from energy via quarks and leptons.

Quarks

Fundamental particles that combine to form protons and neutrons.

Leptons

Fundamental particles that include electrons.

Hydrogen and Helium (atoms formed after cooling)

The light elements formed in the early universe; neutral atoms form when electrons join nuclei after cooling (~380,000 years).

Gravity

The force that pulls masses together; it is stronger where there is more mass and drives the collapse of gas clouds into denser regions.

Density fluctuations

Tiny differences in density in the early universe that seed the growth of structure.

Structure formation

The growth of cosmic structure (stars, galaxies) from gravity acting on density fluctuations.

Second Law of Thermodynamics

The principle that total entropy tends to increase; local pockets of order can emerge due to energy flows, but overall disorder grows.

Complexity and fragility

The idea that increasing complexity brings greater vulnerability to perturbations and environmental changes.