Modules 1-4 PHY 120 Study Guide

Universe

The vast expanse that contains all of space, time, matter, and energy, including billions of galaxies.

Milky Way

Our galaxy, which is home to over 250 billion stars.

Big Bang Theory

The current best theory explaining the origin of the universe, proposing that matter was concentrated in a single point before exploding.

Doppler Shift

Change in the wavelength (or frequency) of light or sound, often observed as a shift toward red or blue depending on whether an object is moving away or toward the observer.

Redshift

The phenomenon where the light from an object moving away from the observer shifts toward the red part of the spectrum.

Hydrogen and Helium

The two lightest elements formed shortly after the Big Bang that combined to create the first stars and galaxies.

Seismic Waves

Waves of energy that travel through the Earth, used to understand its internal structure and composition.

Plate Tectonics

The theory that describes the movement of large pieces of the Earth's lithosphere, which includes both the crust and the upper mantle.

Continental Drift

A theory that describes how continents have moved over geological time, initially proposed by Alfred Wegener.

Volcanic Hazards

Potentially dangerous natural phenomena associated with volcanic eruptions, such as lava flows, ash clouds, and pyroclastic flows.

Lahars

Volcanic mudflows composed of water mixed with volcanic ash and debris, often triggered by melting snow or heavy rains.

Pyroclastic Flow

A fast-moving current of hot gas and volcanic matter that flows down the sides of a volcano during an explosive eruption.

Magma

Liquid rock located beneath the Earth's surface; upon reaching the surface, it is called lava.

Igneous Rocks

Rocks formed from the cooling and solidification of magma or lava.

Sedimentary Rocks

Rocks formed from the accumulation and compacting of sediments, often found in layers.

Metamorphic Rocks

Rocks that have undergone transformation due to heat, pressure, and chemically active fluids.

Seafloor Spreading

The process where new oceanic crust is created at mid-ocean ridges as tectonic plates diverge.

Paleomagnetism

The study of the magnetic properties of rocks, which provides evidence for plate tectonics and changes in the Earth's magnetic field.

Asthenosphere

The upper layer of the Earth's mantle, which is involved in tectonic plate movement and has plastic-like properties.

Cinder Cone Volcano

A type of volcano built from pyroclastic fragments; typically small, with steep slopes.

Stratovolcano (Composite Volcano)

A tall, steep-sided volcano formed from alternating layers of lava flows and pyroclastic material, known for explosive eruptions.

Shield Volcano

A broad, gently sloping volcano built from low-viscosity basaltic lava, characterized by non-explosive eruptions.