Origin of the Universe and Solar System – Vocabulary Flashcards

Vocabulary flashcards covering religious and scientific theories of the origin of the universe and the solar system, plus key Solar System concepts.

Christian Cosmology

Religious cosmology that explains the origin of the universe; God created the heavens and earth (Genesis opening line: 'In the beginning God created the heavens and the earth').

Mormon Cosmology

Belief that human spirits are literal children of Heavenly Parents; spirits created an eternal, beginningless intelligence.

Buddhist Cosmology

Belief that the universe exists because of the karma of beings; no beginning or end to the universe.

Islamic Cosmology

Belief that God created the universe including Earth and humans; cosmos viewed as a book of symbols for meditation and spiritual upliftment.

Hindu Cosmology

Belief that creation is timeless with no beginning; cycle of creation, destruction, and re-creation in eternal loops.

Steady State Theory

Cosmological model in which the universe is unchanging in time and uniform in space; proposes continuous creation; infinity in time and space.

Big Bang Theory

Cosmological model proposing the universe expanded from a singularity about 13.7 billion years ago; Georges Lemaître proposed the idea.

Inflation Theory

Idea that the early universe underwent a brief period of exponential expansion; addresses flatness, monopoles, and horizon problems.

Nebular Hypothesis

Idea that a great cloud of gas and dust (nebula) collapsed under gravity to form the Solar System; proposed by Kant and Laplace.

Solar Nebular Model

Extension of the nebular hypothesis; explains formation of planetesimals and protoplanets from a protoplanetary disk; resolves issues in Kant–Laplace theory.

Vortex Theory

Early theory (Descartes) that the solar system formed from whirlpool-like motion of pre-solar material.

Encounter Hypothesis

Idea (Buffon; Jeans & Jeffreys) that planets formed from material torn from the Sun by a close encounter or collision.

Multiverse Theory

Idea that our universe may be just one of many universes existing parallel to each other.

String Theory (Theory of Everything, TOE)

Hypothetical framework where fundamental blocks are one-dimensional strings; aims to unify all forces and particles.

Cyclic Model

Theory (Steinhardt & Turok) proposing the universe undergoes endless cycles of big bangs and crunches.

Hubble’s Law

Observation that galaxies drift away from us with a recessional velocity proportional to their distance (redshift).

Cosmic Microwave Background (CMB)

Radiation leftover from the early universe, detected as a pervasive background; key evidence for the Big Bang.

Abundance of Light Elements

Observable quantities of helium, hydrogen, and trace amounts of lithium and beryllium in the universe, supporting Big Bang nucleosynthesis.

Flatness (Flatness Problem)

Cosmological finding (WMAP) that the universe is geometrically nearly flat, implying fine-tuning in initial conditions.

Monopole (Magnetic Monopole)

Hypothetical magnetic charge; inflation theory predicts a greatly reduced, undetectable density of monopoles.

Horizon Problem

Question of why distant regions of the universe have nearly identical CMB temperatures despite seeming lack of causal contact in the early universe.

Planck Time

Approximately 10^-43 seconds after the Big Bang; earliest time described by modern physics; gravity separates and forces begin to distinguish.

End of GUT

Around 10^-35 seconds after the Big Bang; strong force separates; electromagnetic and weak forces unify; quarks/leptons form.

Nucleosynthesis

Process around ~100 seconds after the Big Bang when light elements like helium and deuterium form.

Recombination

About 380,000 years after the Big Bang when matter and radiation decouple and matter begins to dominate.

Galaxy Formation

Era about 500 million years after the Big Bang when galaxies and large-scale structures form.

Solar System Formation

Formation of the Sun and planets from the solar nebula (8.5–9 billion years after the Big Bang per notes).

Terrestrial Planets

Rocky planets (Mercury, Venus, Earth, Mars) formed closer to the Sun from rocky material.

Jovian (Gas Giant) Planets

Gas giant planets formed beyond the frost line from gas and ices; include Jupiter, Saturn, Uranus, Neptune.

Frost Line (Ice Line)

Distance from the Sun where volatiles condense into ices (water, methane) enabling rapid growth of giant planets.

Planetesimal

Small solid bodies formed by dust/ice sticking together; building blocks of protoplanets.

Protoplanet

Large body formed by accretion of planetesimals; a precursor to a planet.

Bode’s Law

Empirical rule suggesting a pattern for planetary distances from the Sun.

Near-Circular Orbits

Describes nearly circular planetary orbits in the Solar System.

Coplanarity

Planets orbit roughly in the same plane around the Sun.

Counterclockwise Rotation

Many planets rotate counterclockwise when viewed from above the Sun's north pole.

Retrograde Rotation

Unusual planetary rotation direction; notable examples are Venus and Uranus.

Asteroid Belt

Region between Mars and Jupiter filled with rocky bodies; remnants from early Solar System formation.

Kuiper Belt

Disk-shaped region beyond Neptune, 30–50 AU from the Sun; contains dwarf planets and comets.

Oort Cloud

Spherical shell of icy bodies surrounding the Solar System, extending from ~2,000 to 100,000 AU.

Solar System Characteristics

Near-circular orbits, coplanarity, mostly prograde motion, Bode’s Law patterns, and a mix of rocky and gas giants.