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• The most popular theory of our universe's origin centers on a cosmic cataclysm unmatched in all of history—the Big Bang
• Big bang proponents suggest that some 10 billion to 20 billion years ago, a massive blast allowed all the universe's known matter and energy—even space and time themselves—to spring from some ancient and unknown type of energy
• The expansion has apparently continued, but much more slowly, over the ensuing billions of years
• Big Bang Theory


  Theory that the universe began from a single primordial atom
• Big Bang Theory

  • Edwin Hubble observed that galaxies are speeding away from us in all directions
  • It received significant boosts from the discovery of cosmic microwave radiation by Arno Penzias and Robert Wilson
• The glow of cosmic microwave background radiation, which is found throughout the universe, is thought to be a tangible remnant of leftover light from the big bang
• The Big Bang Theory leaves several major questions unanswered, including the original cause of the Big Bang itself
• Astronomers have acquired the first direct evidence that gravitational waves rippled through our infant universe during an explosive period of growth called inflation
• The findings were made with the help of NASA-developed detector technology on the BICEP2 telescope at the South Pole, in collaboration with the National Science Foundation
• Our universe burst into existence in an event known as the Big Bang 13.8 billion years ago
• Moments later, space itself ripped apart, expanding exponentially in an episode known as inflation
• The gravitational waves produced a characteristic swirly pattern in polarized light, called "B-mode" polarization
• Copernicus placed the planets in circular paths around the sun and put the Earth as the sixth planet with its satellite, the moon
• Nebular Hypothesis


  Theory that the solar system developed with the observed regularities in its motions
• Planetesimal Theory


  Theory that the planetary system was formed from materials removed from the sun by tidal action caused by a passing star
• Dust Cloud Theory


  Theory that the nebula was assumed to have a composition mainly of hydrogen and helium, like the sun, with only 1% of heavier elements
• Protoplanet Hypothesis


  Theory that the original nebula was so massive that on further contraction and flattening, it broke into separate clouds or protoplanets
• Solar system


  Built upon several layers of materials left behind during the stellar formation of the sun
• Terrestrial planets

  • Mercury
  • Venus
  • Earth
  • Mars
• Gas giants

  • Jupiter
  • Saturn
  • Uranus
  • Neptune
• Earth's structure

  • Crust
  • Mantle
  • Core

  
• Parts of the Earth

  • Lithosphere
  • Hydrosphere
  • Biosphere
  • Atmosphere
• Lithosphere


  • Rocky crust of the Earth
  • Inorganic and composed mainly of different kinds of minerals
• Hydrosphere


  • All the waters which circulate on Earth
  • Includes oceans, seas, rivers, lakes, and moisture in the air
• Atmosphere


  • Mass of air surrounding the planet
  • Subdivided into different layers of different densities
  • Comprised of 79% Nitrogen and fewer than 21% Oxygen
• Atmosphere


  • Held to Earth by gravity and thins rapidly with altitude
  • Supports life by regulating climate and providing oxygen and carbon dioxide
• Biosphere


  • All living organisms, from smallest bacteria to largest whale
  • Includes uppermost geosphere, hydrosphere, and lower parts of atmosphere
• Organisms are affected by Earth's environment and also alter and form the environment they live in
• Characteristics necessary to support life

  • Water
  • Energy
  • Time
  • Recycling
• Water


  • Excellent solvent capable of dissolving many substances
  • Floats when frozen, allowing underlying fluid to remain liquid
• Energy


  • Needed for life to happen
  • Can come from host star or other sources like deep-water vents
• Time


  • Habitable worlds need stars that can live at least several billion years
  • Life may evolve quickly but more complex forms take longer
• Recycling


  Plate tectonics helps recycle molecules like carbon dioxide that life needs
• Earth remains the only known planet to host life, due to a unique combination of factors
• George Lemaitre



  belgian priest that suggested that the universe began from a single primordial atom
• Cosmic microwave background radiation


  Oldest radiation known, may hold many secrets about the universe's earliest moments
• Sun - 4.6 billion years old

  Solar system - 4.5 billion years old

  Milky way - 13.2 billion years old
• Inflation theories


  the universe expanded by 100 trillion times in less than the blink of an eye
• Planck satellite, a European Space Agency mission for which NASA provided detector and cooler technology, confirmed the basic theory of the universe(existence of inflation and cosmic microwave background radiation
• Jamie Bock of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., which developed the BICEP2 detector technology.