Scientific Origins of the Universe and Solar System

17 vocabulary flashcards covering key scientists, theories, discoveries, and composition of the universe and solar system.

Geometric Theory of Gravitation (General Relativity)

Albert Einstein’s theory describing gravity as the curvature of spacetime.

Hubble Plot

Edwin Hubble’s graph showing that more-distant galaxies recede faster, revealing the universe’s expansion.

George Lemaître

Belgian priest-physicist who first presented the Big Bang idea in scientific form in .

Big Bang Theory

Model (term coined by Fred Hoyle) stating the universe began hot and dense and has expanded for ~13.7 billion years.

Singularity (Cosmology)

Extremely small, hot, dense state from which the universe began expanding.

Cosmic Microwave Background (CMB)

Faint microwave radiation discovered by Arno Penzias and Robert Wilson in 1965, remnant of the Big Bang.

Cosmic Expansion

Observation that galaxies are moving away from each other, evidencing an expanding universe.

Hydrogen

The first chemical element formed after the Big Bang.

Helium

Second lightest element, created alongside hydrogen in the early universe.

Universe (Cosmology)

Totality of spacetime, matter, and energy.

Dark Energy

Mysterious form of energy making up about 68 % of the universe and driving accelerated expansion.

Dark Matter

Invisible matter accounting for roughly 27 % of the universe’s mass-energy content.

Ordinary (Baryonic) Matter

Atoms and molecules composing stars, planets, and life—about 5 % of the universe.

Milky Way Galaxy

Spiral galaxy containing our solar system; second largest member of the Local Group.

Local Group

Collection of ~50 galaxies including the Milky Way, Andromeda, and Magellanic Clouds.

Nebular Theory

Explanation that the solar system formed from a rotating cloud of gas and dust (nebula).

Emmanuel Swedenborg (1734)

Proposed a nebular origin of the solar system in ‘On the Principles of Natural Things.’