Dainius Slotkus

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The Big Bang Theory

• Dainius Slotkus

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Introduction to the Big Bang Theory

• The Big Bang theory is a theory about the origin
  of our universe.
• The theory states that the universe had expanded
  from a point only a few millimeters across.
• The bang is said to have occurred 12 to 14
  billion years ago.
• This theory is based on the ideas of General
  Relativity and the Cosmological Principle.

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General Relativity and the Cosmological Principle

• The Big Bang theory involves two major ideas
  General Relativity and the Cosmological
  Principle.
• General Relativity
• The General Theory of Relativity was developed
  by Albert Einstein in 1916. This theory expands
  upon the original theory of gravity that was
  proposed by Isaac Newton. One of the important
  ideas suggested by the General Theory of
  Relativity is that gravity is a distortion of
  space and time.
• The Cosmological Principle
• The Cosmological Principle refers to the
  assumption that matter is distributed uniformly
  throughout the universe when averaged over very
  large scales. This applies to the distribution of
  galaxies as well as cosmic microwave background
  radiation, which refers to the remnant heat from
  the Big Bang.

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The Big Bang Theory in Detail

• According to the standard Big Bang theory, the
  universe began as a singularity- a zone of
  infinite density. This singularity expanded and
  cooled from its extremely hot temperature, and
  continues to expand today.
• The Big Bang theory is supported by various
  evidences. One is the fact that galaxies appear
  to be moving away from us at speeds proportional
  to their distance. Another is the existence of
  Cosmic Microwave Background radiation, which is
  believed to be the remnant of the powerful heat
  that existed in the singularity.

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The Big Bang Theory in Detail(continued)

• Another concept relating to the Big Bang is the
  Big Crunch.
• The Big Crunch represents the idea that
  eventually, the universe might stop expanding and
  might begin to contract. Gravity would cause this
  to happen.
• If the universe contracts, gravity might cause it
  to collapse completely and become a singularity
  again. After this, there might be another Big
  Bang.

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Common Misconceptions about the Big Bang Theory

• One misconception is that the Big Bang was a
  massive explosion. In fact, the Big Bang theory
  does not describe the event as an explosion, but
  as expansion.
• Another misconception is that the Big Bang theory
  can explain what is beyond the universe. The Big
  Bang theory does not describe what the universe
  is expanding into. In other words, it doesnt
  describe what is beyond the universe.

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Expansion of the Universe

• Some scientists think that the universes
  expansion is accelerating.
• Scientists came up with this idea after studying
  the brightness of distant supernovae.
• Studying the brightness of distant supernovae
  involves studying the redshift of the
  supernovae. Redshift is a term that is involved
  in the Doppler effect.

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Timeline of the Big Bang

• Here are a few of the events on the timeline of
  the Big Bang
• One millionth of a second after the Big Bang,
  forces like gravity and electromagnetic forces
  formed.
• 3 minutes after the Big Bang, basic elements such
  as hydrogen and helium began to form.
• Stars and galaxies began to form 300 million
  years after the Big Bang.

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Dark Matter

• Dark matter refers to non-luminous, undetectable
  particles of matter that are thought to exist.
• Dark matter is believed to exist within galaxies,
  because something has a gravitational effect on
  the rotation rate of galaxies.

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Sources of Information

• www.thirteen.org
• http//map.gsfc.nasa.gov
• www.big-bang-theory.com
• www.windows.ucar.edu
• www.astro.ucla.edu
• www.pbs.org