Big Bang Theory

• Big bang theory


  The leading explanation for the origin of the universe.
• How did the universe begin

  It began approximately 13.8 billion years ago, from an extremely hot dense state and has been expanding ever since
• Singularity


  A point of infinite density and temperature
• Cosmic inflation 


  An event where rapid expansion occurred
• As the universe expanded it cooled allowing energy to convert into matter and antimatter. Over time, matter clumped together to form stars, galaxies, and other cosmic structures.
• Big bang nucleosynthesis


  A process as explained by the big bang theory that explains the creation of light elements
• During the first few minutes of the universe:

  • Temperatures were extremely high (~10 billion Kelvin) that enabled nuclear reactions
  • The universe expanded and cooled rapidly, creating suitable conditions for the formation of light nuclei
  • Neutrons and protons combined to form the first atomic nuclei but the extreme heat prevented the formation of heavier elements
• Light elements


  The elements with the lowest atomic numbers and masses. Formed through big bang nucleosynthesis. Protons and neutrons combine under high temperature and pressure.
• Hydrogen-1: the simplest and most abundant element in the universe

  Hydrogen-2: a heavier isotope of hydrogen

  Helium-3: a lighter isotope of helium

  Helium-4: the most stable and abundant isotope of helium

  Lithium-7: light element formed in trace amounts
• Quarks


  Building blocks of atoms, it makes up protons and neutrons which are found in atom's nucleus
• Quark-Gluon plasma

  1. In the earliest moments the universe consisted of a hot soup of quarks and gluons
  2. As the universe could quarks combine to form protons and neutron
• Formation of nuclei


  1 . 1 second after the big bang the temperature drop enough for nuclear reactions to begin.

  Neutrons and protons used to form deuterium (Hydrogen-2)
• At the end of the nucleosynthesis

  1. After 20 minutes the universe cooled to a point where nuclear fusion could no longer occur how think the formation of additional light elements
  2. The remaining matter was mostly hydrogen and helium with traces of lithium and other light isotopes