Earth Science Week 1 Lesson 1: The Universe and the Solar System

Vocabulary flashcards covering key terms from the lecture notes on the Universe and the Solar System.

The Universe

The total of all space, matter, energy, and phenomena that exists.

Big Bang Theory

The universe began from a single, hot, dense point about 13.8 billion years ago and has been expanding and cooling since.

Singularity

A point of infinite density and heat from which the Big Bang originated.

Redshift

The stretching of light to longer wavelengths from distant galaxies, evidence for universal expansion.

Cosmic Microwave Background Radiation

A faint afterglow left from the early universe, supporting the Big Bang theory.

Abundances of Elements

The observed distribution of light and heavy elements in the universe, used as evidence for the Big Bang.

Fred Hoyle

English astronomer who coined the term 'Big Bang' in 1949; he opposed the theory.

Pulsating Theory

A variation of the Big Bang proposing endless cycles of expansion and contraction; requires critical density.

Critical Density

The density of the universe needed for the pulsating model to occur; not yet proven.

Nebular Theory

The Sun, Earth, and rest of the solar system formed from gravitational collapse of a solar nebula about 4.6 billion years ago.

Solar Nebula

The rotating cloud of gas and dust that collapsed to form the solar system.

Kant

German philosopher who first proposed the nebular hypothesis in 1755.

Laplace

French scientist who refined the nebular hypothesis in 1796.

Nebular Collapse Processes

Three processes: temperatures increased, the nebula spun faster, and the solar nebula disk flattened.

Solar System Formation

Formation of the Sun and planets from the collapsed solar nebula due to gravity and subsequent differentiation.

Oscillating Universe

A concept from Rigveda describing a universe that expands and contracts cyclically.

Bramanda

Cosmic egg containing the whole universe in Hindu cosmology.

Bindu

The single concentrated point from which the universe expands in Hindu cosmology.

Anaxagoras

Greek philosopher who described a primordial mixture of all ingredients in the early universe.

Primordial Mixture

The original state of the cosmos consisting of all ingredients in infinitesimally small fragments.

Geocentric Model

Earth-centered model of the solar system proposed by Ptolemy.

Heliocentric Model

Sun-centered model of the solar system proposed by Copernicus.

Ptolemy

Ancient astronomer who developed the geocentric model.

Copernicus

Polish astronomer who proposed the heliocentric model.

Model (scientific)

A simplified representation of an idea, object, or process used to describe and explain phenomena.

Continental Drift Theory

Idea that continents move slowly over Earth's surface; proposed by Alfred Wegener and later replaced by plate tectonics.

Plate Tectonics

Modern theory explaining the movement of rigid lithospheric plates on the Earth's surface.

Alfred Wegener

Scientist who proposed continental drift and linked continents by fit, fossils, and geology.

Pangaea

Ancient supercontinent that split into Laurasia and Gondwana.

Laurasia

Northern part of the supercontinent that formed after Pangaea's breakup.

Gondwana

Southern part of the supercontinent that formed after Pangaea's breakup.

Evidence for Continental Drift - Fit of the Continents

Continents match together like puzzle pieces; rock layers align across oceans.

Mesosaurus

A freshwater reptile fossil found in southern Africa and South America, suggesting a past connection.

Svalbard Fossils

Arctic fossils of tropical plants indicating a past warmer climate in the Arctic.

Appalachians and Caledonides

Rock and mountain range connections that support continental connections in the past.

Tethys Ocean

Ancient ocean that existed between Gondwana and Laurasia.

Origin of the Solar System (context)

Formation of the Sun, planets, and other bodies from a collapsing solar nebula.