scts mod 8

• Cosmology


  Study of the origin, evolution & structure of the universe
• Cosmogony


  Study of the origin of the universe
• Cosmology is about describing the past, explaining the present, and predicting the universe's future.
• Prehistoric and Ancient Astronomy used the positions of stars to assist in navigation, and some of these observations were of an astrological nature

  
• Ancient Egyptians developed a model of the universe in which a flat Earth was covered by a solid dome
• Ancient Greeks divided the universe into terrestrial spheres, which were corruptible and where humans lived, and the celestial spheres in which the planets and stars revolve around the earth
• Ancient Greeks believed that the Earth is the center of the universe.
• Aristotle deduced that the Earth and Moon are spherical, that the Sun is much farther from the Earth than the Moon is, and that the distance from the Earth to the stars is much greater than the Earth's diameter

  
• Claudius Ptolemy proposed an Earth-centered cosmology
• Nicolaus Copernicus revolutionized the study of the universe by proposing a heliocentric model that replaced the Earth-centered two-sphere model
• Copernicus' heliocentric model had the revolution of heavenly bodies where the Sun is stationary and the earth and the five known planets moved in circular orbits around the Sun.

  
• Galileo Galilei used a telescope to study the heavens and provided the observational proof of the Copernican heliocentric model

  
• Galileo Galilei made observations of gravity, light, and the distance from the moon to the Earth

  
• Isaac Newton discovered the law of universal gravitation, which could explain the motion of the Sun and planets
• Isaac Newton discovered the planet Uranus, studied the structure of the Milky Way, and proposed the first model of the galaxy

  
• Sir William Herschel applied spectrum analysis to astronomy and showed that stars are composed of the same elements as the Sun and Earth

  
• Sir William and Margaret Huggins developed theories of relativity that can be considered as the birth of modern cosmology
• Albert Einstein developed the theories of special and general relativity
• Edwin Hubble discovered the "Andromeda Galaxy" which is 900,000 lightyears away from Earth, and discovered that the universe is expanding - the Big Bang

  
• Georges Lemaitre proposed the steady-state model, while Fred Hoyle coined the term "Big Bang"
• The Big Bang Theory describes the expansion and evolution of the universe from an initially hot and dense state to its current relatively cool and tenuous state, and still expanding until today
• The Hubble Law states that the farther away a galaxy is, the more its spectrum appears shifted into the red, and the expansion rate is given by v = H0d

  
• The cosmological principle states that the Universe is homogeneous and isotropic on very large scales
• George Gamow first supported the idea of a "Hot Big Bang" and predicted the existence of a leftover remnant of that initial radiation
• Penzias and Wilson accidentally made the discovery of the Cosmic Microwave Background, which placed the Big Bang Theory on firm footing
• The age of the universe is 13.8 billion years, calculated from the expansion time being equivalent to the age of the universe
• Light is an electromagnetic wave that travels at 186,000 miles per second, allowing us to see into the past
• Gravitational instability, density fluctuations in the early universe, and hierarchical structure formation provide the "seeds" from which all structure in the universe developed
• Dark matter accounts for 85% of all the matter in the universe, forms first in the early universe, and provides the "framework" onto which ordinary matter collapses to form stars and galaxies
• Cosmic inflation offers solutions to the flatness and smoothness problems of the Big Bang theory, and explains why the universe is full of stars and planets
• Dark energy makes up approximately 70% of our universe and is causing the universe's rate of expansion to accelerate
• The timeline of the universe includes the Big Bang, inflation, the cosmic microwave background, the dark ages, the formation of the first stars, and the accelerating universe driven by dark energy