01 ORIGIN AND STRUCTURE OF THE EARTH

• Cosmology


  Branch of astronomy that deals with the origin and evolution of the universe and its future at its largest scales

  
• Cosmogony


  Branch of science (under cosmology) that deals with the origin of the universe especially the solar system
• Theological Perspective on the Birth of the Universe

  • Christian Belief
  • India's Rigveda
• Christian Belief


  Uses the Book of Genesis as basis for the creation of the Universe
• India's Rigveda


  Describes the universe an oscillating universe with Brahmanda (Cosmic Egg) and collapses as Bindu (Point) then reincarnates as new Brahmanda
• Greek Philosophy on the Birth of the Universe

  • Anaxagoras
  • Leucippus & Democritus
  • Aristotle & Ptolemy
• Anaxagoras


  Everything came from a primordial universe
• Leucippus & Democritus


  Everything is made of indestructible particles called "atomos"
• Aristotle & Ptolemy


  Geocentrism (earth is the center of the cosmos)
• Scientific Shift on the Birth of the Universe

  • Nicolaus Copernicus
  • Isaac Newton
  • Rene Descartes
• Nicolaus Copernicus


  Heliocentrism (sun is the center of the cosmos)

  
• Isaac Newton


  Steady-state universe
• Rene Descartes


  Agreed with Newton's steady-state theory
• The Big Bang Theory is a widely-accepted theory in cosmogony
• Big Bang Theory


  Describes how the universe, and everything within it, came into existence from an incredibly small and dense point called a singularity, which occurred 13.8 billion years ago

  
• There was NO "bang" or explosion during the Big Bang. Instead, there was a rapid exponential expansion of a very condensed point in space.
• Supporting Evidences for the Big Bang Theory

  • Cosmic Microwave Background
  • Galactic Red-shifting
• Cosmic Microwave Background


  A leftover radiation from the time when the universe began, discovered by Arno Penzias and Robert Wilson
• Galactic Red-shifting


  Redshift is an increase in the wavelength of electromagnetic radiation, which shows that the Universe is expanding, with galaxies moving away from each other at a velocity given by the expression: v = Hod

  
• Theories and Hypotheses on the Birth of the Universe

  • Big Bang Theory
  • Steady-State Theory
  • Oscillating Universe Theory
  • Eternal Inflation Theory
• Steady-State Theory

  Proposed that the universe has always been and will always be the same, with new matter being added to retain its density despite expansion
• Oscillating Universe Theory


  The universe currently exists between the big bang and the big crunch (one of the predicted ends of the universe), and the current universe is just one of the many series of universes created by a cycle of big bangs and big crunches
• Eternal Inflation Theory


  Proposed by Alan Guth, introduced a short early period of exponential cosmic inflation which served to solve some complications in the Big Bang
• Theories and Hypotheses on the Origin of the Solar System

  • Encounter Hypothesis/Planetesimal Theory
  • Protoplanet Hypothesis
  • Nebular Hypothesis
  • Solar Nebula Theory

  
• Encounter Hypothesis/Planetesimal Theory


  States that about five (5) billion years ago, the sun encountered a hypervelocity rogue star, and the stripped material coalesced into planets

  
• Protoplanet Hypothesis


  Suggests that a cloud of gas and dust, about 10 million kilometers in diameter, rotated slowly, and on further contraction and flattening, it broke into separate clouds or protoplanets
• Nebular Hypothesis


  Proposed that the Solar System was formed from a slowly-rotating cloud of gas or nebula that collapsed and flattened

  
• Solar Nebula Theory


  A more sophisticated version of the nebular hypothesis, combining the idea of a flattening solar nebula with that of a condensing interstellar dust as the nebula cooled, which serves as a condensation nuclei where matter accumulated

  
• Earth Spheres


  • Hydrosphere
  • Atmosphere
  • Geosphere/Lithosphere
  • Biosphere
• Hydrosphere


  The water portion, making up 71% of Earth's surface, mostly saltwater, and interacting with the geosphere through the water cycle
• Atmosphere


  The gaseous envelope surrounding our planet, held together by gravity and regulating climate by acting as a blanket and filter
• Geosphere/Lithosphere


  The solid component, comprising the visible solid layer and extending to the center of the Earth, including the crust, mantle, and core
• Biosphere


  The living component, comprising all living organisms (plants, animals, and single-celled organisms)
• Requirements for a Habitable Planet

  • The central star should survive long enough for its planets to develop life
  • The planet should exist in a region where water could remain liquid (Goldilocks Zone/Habitable Zone)
• Other Requirements for a Habitable Planet

  • Water
  • Energy
  • Time
  • Plate Tectonics
  • Magnetic Field