Astronomy and Our Origins

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Astronomy and Our Origins
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Where did we come from?

• Scientists believe the entire universe began as a
  single, one dimensional speck that exploded into
  existence.
• This idea is called the Big Bang Theory!
• Do we know for sureof course notwe could be
  right or wrong. We will never know.
• But we do have a lot of evidence to support our
  hypothesis.

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• That explosion caused everything in the universe
  to spread apart and speed away from each other.
• This spreading apart is occurring today and can
  be measured.
• If we wind the clock backwards, we believe the
  age of the universe to be 13.7 billion years old.

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• Doppler Effect the change in frequency emitted
  from a moving object.
• For moving sound sources (race cars, sirens, etc)
  the pitch (highness/lowness) changes.
• For moving light sources (stars, galaxies, etc)
  the light color changes.

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• Doppler Effect
• Things moving away shift to
• Redder colors longer distances longer
  wavelengths red shift
• Things moving towards us shift to
• Bluer colors shorter distances shorter
  wavelengths blue shift

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• Countless stars formed, lived and exploded a
  violent death, spewing their guts into the
  universe.

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• This is an actual star explosion that occurred in
  1054

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• Eventually gravity caused a section of all this
  left over star material to spin, clump together
  and form the sun, planets, and our whole solar
  system.
• This process is called the nebular hypothesis.
• Everything in space spins and moves in lots of
  different ways.
• Earths motions include rotation, revolution,
  and precession, and others.

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Formation of our solar system nebula
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Nebula