Earth Science 1: The Universe and the Solar System

Creation Myth

is a symbolic narrative of the beginning of the world as understood by a culture.

Big Bang Theory

• formulated by Alexander Friedmann and George Lemaitre in 1920.

• this hypothesis states that all of the current matter in the Universe came into existence at the same time, roughly 13.8 billion years ago

• states that all matter was compacted into a small ball with infinite density and intense heat called singularity. Suddenly, the singularity began expanding and the universe as we know it began. 

Inflationary Epoch

 universe expanded from the size of an atomic nucleus to 1035 meters in width.

Formation of the Universe

the universe continued to expand

Formation of Basic Elements

 protons and neutrons combined to form hydrogen nuclei. Then hydrogen began to combine in pairs to form helium nuclei. The process is nucleosynthesis.

Radiation Era

 most energy in the universe was in the form of radiation, they formed what was called the cosmic microwave background radiation

Matter domination

 matter began to dominate at the end of radiation era, lithium atom began to be formed.

Birth of stars and galaxies

gas cloud attracted nearby matter and became denser. The dense gas clouds collapsed and gained enough mass to produce light

Gas cloud

 this could be the birthplace for dozens of stars.

Group of Stars

become the galaxies

Strong force

 short ranged attractive force which binds the nucleus

Electromagnetic Force

long-ranged force that binds atoms which can either be attractive or repulsive

Weak Force

short-ranged force present in radioactive decay

Gravitational Force

weak, long-ranged, and attractive force which bind the solar system

Edwin Hubble (1942)

found that stars are not uniformly distributed in space. Instead, they gather together, forming clusters called galaxies. He found out that nearly all galaxies were moving away, with the distance between distant galaxies increasing with time.

Arno Allan Penzias and Robert Woodrow Wilson (1960)

 discovered a background radio emission coming from every direction in the sky. The discovery of CMB placed an end to the steady state theory of the universe. 

Flatness

Wilkinson Microwave Anisotropy Probe (WMAP) revealed that the geometry of the universe is nearly flat. However, according to the Big Bang theory, there should be curvature as time grows

Monopole

big bang theory predicted the production of heavy stable magnetic monopoles in the early universe. However, there were no magnetic monopoles that have been observed.

Horizon

based on the big bang expansion, distant regions of space in opposite directions of the sky are so far apart that they could never have been in causal contact with

Steady State Theory

• proposed by Herman Bondi, Thomas Gold, and Fred Hoyle in 1948.

• the universe is unchanging in time and uniform in space

• the discovery of CMB contradicted the assumption of SST that everything is contract. 

Inflation Theory

• proposed by Alan Guth, Andrei Linde, Paul Steinhart, and Andy Albrecht

• offered solutions to the unresolved problems revolving the big bang theory.

• proposed a period of exponential expansion of the universe prior to the more gradual big bang expansion

Descartes’ Vortex Theory

• french mathematician and physicist Rene Descartes was one of the first proponents of a model on the origin of the Solar System.

• the Solar System was formed into bodies with nearly circular orbits because of the whirlpool-like motion in the presolar materials. 

• he explained the orbits of the planets are the primary whirlpool motion and the satellites the secondary whirlpool motion.

Buffon’s Collision Theory

• 18th century French naturalist George-Louis Leclerc, Comte de Buffon proposed that the planets were formed by the collision of the sun with a giant comet. 

Kant-Laplace Nebular Theory

• Based on the ideas of Descartes, Immanuel Kant and Pierre Simon Laplace proposed the nebular theory which suggested that a great cloud of gas and dust, called nebula, began to collapse because of gravitational pull. As the cloud contracted, it spun more rapidly. 

• The spinning cloud fattens into a pancake-shaped object with a bulge at the center. As the nebula collapses further, local regions contract on their own due to gravity. These local regions became the sun and the planets.

Jeans-Jeffrey’s Tidal Theory

• Sir James Hopwood Jeans and Harold Jeffreys suggested a dualistic theory in which the sun and planets were produced by different mechanisms.

• Their theory is known as tidal theory. The tidal theory proposed that the planets were formed from the substance that was torn out of the sun.

• As a speeding massive star passed near the sun, it pulled off material due to gravitational attraction. The torn-off material subsequently condensed to form the planets.

Solar Nebular Theory

• main conern is to solve the original problems of Kant and Laplaces nebular hypothesis about angular momentum of the sun.

• was formed as a result of the condensation of hydrogen gas and dust referred to as interstellar gas and dust cloud.

Asteroids

• Are made up of rocks and are sometimes reffered to as minor planets in many ways. They are atmosphere-free and they orbit around the sun. They tend to congregate in what is known as main asteroid belt. 

Main asteroid belt

located between the orbits of Mars and Jupiter

Comets

• Are composed of mainly ice (frozen water and gas) and nonvolatile dust (silicate minerals and carbon grains). 

• They only become active when their orbits take them near the sun. The sun's heat causes the frozen gases to sublimate, forming vaporous jet of streams. These vapor jets create a spectacular tail streaming out from the sun.

• Originate from two regions of the outer Solar System

Kuiper Belt

often called the solar system’s “final frontier” because it is at the outermost region of the solar system.

Short period comets

ort the sun in less than 200 years. / like Halley's comet come from the Kuiper belt.

Oort Cloud

located farther than the Kuiper belt and, therefore, remained unexplored.

Long period comets

are thought to originate from the Oort cloud.

Terrestrial Planets

are Earth-like planets, which include Mercury, Venus, Earth, and Mars. They are sometimes referred to as inner planets. They are composed mostly of dense, rocky, and metallic materials.

Jovian Planets

1. are Jupiter-like planets, which include Jupiter, Saturn, Uranus, and Neptune. They are reffered to as gas planets and are made up mostly of hydrogen and helium.