Cosmology Theories Overview

Big Bang Theory

• States the universe originated as a single point, expanding and stretching continuously.
• Cannot explain what existed before the universe's creation.
• Began with hot, tiny particles and energy, cooled, formed atoms, stars, and galaxies.
• 13.8 billion years old.
• Evidence: redshift (universe expansion), light element abundance, cosmic microwave background radiation.

Steady State Theory

• Proposes a universe unchanging over time.
• Based on the Perfect Cosmological Principle (infinite extent, age, and uniformity).
• Acknowledges change on smaller scales (new star formation replacing dying stars).

Cosmic Inflation Theory

• Suggests the universe continues creating other universes (multiverses) after the Big Bang.

Big Crunch Theory

• Suggests the universe's expansion will stop and collapse into a singularity (a massive black hole).

Origin of the Solar System

• Descartes' Vortex Theory: Planets orbit in nearly circular paths due to whirlpool-like motions in pre-solar material.
• Buffon's Collision Theory: Planets formed from the sun colliding with a comet.
• Kant-Laplace Nebular Theory: A gas and dust cloud (nebula) collapsed due to gravity, forming the sun and planets.
• Jeans-Jeffreys' Tidal Theory: A passing star pulled material from the sun, forming planets.
• Solar Nebular Theory: A supernova caused a cloud collapse, creating the sun and planets.

Redshift and Blueshift

• Redshift: An object moving away from us.
• Blueshift: An object moving towards us.

Earth System

• A closed system; energy passes across boundaries, but not mass.
• Consists of interconnected subsystems.

Hydrosphere

• Covers 71% of Earth's surface.
• 3% freshwater (⅔ ice, ⅓ streams/lakes/groundwater).
• 97% saltwater.
• Continuously cycles.

Atmosphere

• Earth's gaseous envelope.
• Exchange of energy with the surface and space creates weather and climate.
• Primarily nitrogen (78%) and oxygen (21%).

Geosphere

• Earth's solid, rocky part, largest subsystem.
• Layers: crust, mantle, core.
• Crust types: continental (granitic), oceanic (basaltic).
• Lithosphere (crust + upper mantle), Asthenosphere (molten rocks), Mesosphere (solid rocks).

Biosphere

• All life on Earth.
• Shaped by interactions with other subsystems.

Minerals and Rocks

• Minerals: Naturally occurring, inorganic, homogeneous solids with definite chemical compositions and crystalline structures. Physical properties include color, streak, luster, hardness, cleavage, and fracture.
• Mineraloids: Pass most mineral criteria but lack internal order.
• Rocks: Formed from aggregated minerals.
• Igneous Rocks: Form from cooled magma; classified as extrusive (surface) or intrusive (underground).
• Sedimentary Rocks: Form from weathered and eroded materials. Classified by origin (detrital, chemical, organic).
• Metamorphic Rocks: Formed from existing rocks transformed by heat, pressure, or chemically active fluids.
• Rock Classification Igneous rocks are classified by composition into ultramafic, mafic ,intermediate and felsic.

Deformation of Earth's Crust

• Endogenous Processes: Large-scale processes building and changing landscapes.
• Volcanism: Volcanic eruptions.
• Plutonism: Intrusions of igneous materials.
• Tectonic Processes: Affected by tension, compression, and shear.
• Folding: Bending of rock layers due to compression forces (anticlines, synclines).
• Faulting: Cracks in rocks with movement (normal, reverse, thrust faults; rift valleys, graben, strike-slip).

History of Earth

• Earth is 4.543 billion years old.
• Uniformitarianism: Earth's features formed by natural processes over geologic time.

Relative Dating

• Determines the relative order of events (younger/older than another).
• Qualitative, less specific.
• Method Examples: stratigraphy (layered rocks), biostratigraphy (fossils), cross-dating, fluorine dating.

Absolute Dating

• Determines numerical ages of materials using radioactive isotopes.
• Quantitative and exact.
• Method Example: radiometric dating, half-life.

Geologic Time Scale

• Organized into eons, eras, periods, and epochs.

Fossils

• Preserved remains or traces of organisms.
• Important for understanding life's history and relationships between organisms.
• Index fossils: easily recognized, abundant, with a short lifespan.

Geologic Processes and Hazards

• Earthquakes: Ground shaking from rock movement.
• Hypocenter (focus): Point of initial rock movement.
• Epicenter: Point on the surface above the hypocenter.
• Magnitude: Energy released (measured numerically).
• Intensity: Effects on people and surroundings (measured by roman numerals).
• Volcanic Eruptions: Molten rock, gas, and material ejected from a volcano.
• Hazards: lava flows, tephra/ash, pyroclastic flows, lateral blasts, volcanic gases, lahars, ash clouds.
• Landslides: Mass movement of rock, soil, and debris down a slope.
• Triggers: natural (e.g., earthquakes, water), human (e.g., construction, mining).

Explore various theories about the origins and nature of our universe, including the Big Bang Theory, Steady State Theory, and others. Learn about concepts like cosmic inflation and the fate of the universe with the Big Crunch Theory. This quiz will test your knowledge of these fundamental cosmological ideas.