The Big Bang

• THe universe comprises everything that physically exists.

  It is the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them
• The universe has no boundaries or edges; it's infinite.
• Big Bang Theory - states that the universe began in an infinitely hot and dense point called the singularity it is similar to a supercharged blackhole.
• About 13.7 billion years ago a single point called singulairty exploded creating matter, energy, space and time
• The universe


  Everything, from the tiniest particles to the largest galaxies, including the existence of space, time, and life
• Origin of the universe

  1. Multiple scientific theories plus creation myths from around the world have tried to explain its mysterious genesis

  2. The most widely accepted explanation is the Big Bang theory
• Big Bang theory


  • The universe began as a hot and infinitely dense point, only a few millimeters wide, similar to a supercharged black hole
  • About 13.7 billion years ago this tiny singularity violently exploded
  • All matter, energy, space, and time were created from this explosion
• Two major stages of the universe's evolution

  1. Radiation era

  2. Matter era
• Radiation era


  1. Dominated by radiation right after the Big Bang

  2. Includes smaller stages called epochs that occurred within the universe's first tens of thousands of years
• Epochs within the radiation era

  • Planck epoch
  • Grand unification epoch
  • Inflationary epoch
  • Electroweak epoch
  • Quark epoch
  • Hadron epoch
  • Lepton epoch
  • Nuclear epoch
• Planck epoch


  • No matter existed in the universe at this time, only energy and the ancestor to the four forces of nature, the superforce
  • The superforces are: Gravity, Strong Nuclear, Weak, and Electromagnetic
  • Gravity split away from the superforce
• Grand unification epoch


  • The three remaining unified forces of nature
  • The strong nuclear force broke away
• Inflationary epoch


  • The universe rapidly expanded, almost instantly growing from the size of an atom to the size of a grapefruit
  • The universe was piping hot and churned with electrons, quarks, and other particles
• Electroweak epoch


  The electromagnetic and weak forces finally split off
• Quark epoch


  All of the universe's ingredients were present, but the universe was still too hot and dense for subatomic particles to form
• Hadron epoch


  The universe cooled down enough for quarks to bind together and form protons and neutrons
• Lepton and nuclear epochs


  The protons and neutrons underwent a significant change, fusing and creating the first chemical element in the universe, helium
• Matter era


  • Defined by the presence and predominance of matter in the universe
  • Includes three epochs that span billions of years, the vast majority of the universe's life span, and the present day
• Atomic epoch


  The universe's temperature cooled down enough for electrons to attach to nuclei for the first time---called recombination, creating the universe's second element, hydrogen
• Galactic epoch


  The hydrogen along with helium atoms dotted the universe with atomic clouds

  Within Small pockets of gas within atomic clouds had enough gravity to cause atoms to collect, forming the seedlings of galaxies
• Stellar epoch


  • Stars began to form within the galaxies, causing a tremendous ripple effect and helping shape the universe as we know it
  • Heat within the stars caused the conversion of helium and hydrogen into almost all the remaining elements in the universe
  • Those elements became the building blocks for planets, moons, life, everything we see today
• The cosmic microwave background (CMB) is leftover radiation from the Big Bang or the time when the universe began. 
•  the speed at which astronomical objects move apart is proportional to their distance from each other. In other words, the farther away objects are from Earth, the faster they are moving away from us. This became known as Hubble's law.
• Georges Lemaitre - proposed what became known as Big Bang theory of the origin of the universe, although he called it his hypothesis of the primeval atom.

  The framework for the model relies on Albert Einstein's general elativity.
• Red shift - happens when light seen coming from an object that is moving away from us gets stretched out, and is proportionally increase in wavelength, or shifted to the red end of the spectrum.
• Blue shift - light emitting object tends to appear blue to the observer if they are moving closer.
• Hubble Space Telescope - launched by NASA in April 1990, has been used to observe distant supernovae and measure their brightness. It was named after Edwin Hubble who discovered that the universe is expanding.
• Dark energy - thought to make up about two thirds of the total content of the universe. It causes space itself to expand at an accelerating rate.
• Dark matter - does not interact with electromagnetic radiation such as visible light, radio waves, X-rays, etc., but only through gravity. Its existence can be inferred from its gravitational effects on visible matter.
• Cosmic microwave background (CMB) - remnant heat left over from the big bang. It is the most important piece of evidence supporting the big bang theory.
• Cosmic microwave background radiation (CMB) - electromagnetic radiation left over from the early stages of the universe. It is believed to have formed shortly after the big bang.
• Identify the stages of Radiation era

  A) Plankc

  B) Grand Unified

  C) Inflationary

  D) Electroweak

  E) Quark

  F) Hadron

  G) Lepton

  H) Nuclear

  
• Identify the stages of the Matter era

  A) Atomic

  B) Galactic

  C) Stellar