30.3 Big Bang Theory

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30.3 Big Bang Theory
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Doppler Effect

• _____________________ apparent shift in the
  ________________ of energy emitted by an energy
  source moving away from or towards an observer

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Spectroscope

• Scientists used a _______________ to study what
  elements were in stars
• Spectroscope _______________ that splits white
  light into a band of colors
• Scientists were able to determine
  _________________ make-up of stars

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Red Shift

• Scientists soon found that the _________ of many
  galaxies were shifted toward the _________ end of
  the spectra
• Showed that almost all the galaxies were moving
  _____________ from the Earth
• That means the solar system is still
  ________________

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Theory

• Observing the ________ shift led scientists to
  form a ______________ about the expanding
  universe
• _____________ of years ago, all matter and energy
  was compressed into a small volume
• Sudden event _______________ sent all the
  matter and energy outward
• Some matter gathered in clumps and formed
  _______________

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Big Bang Model

• In the Big Bang model, the of the ____________
  expansion of the universe is opposed by the
  __________ force of gravity acting on the matter
  of the universe to slow that expansion.

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Big Bang Model

• Outward Expansion
• When the rate of expansion of the universe is
  known, it is possible to calculate the time since
  the expansion started and determine the _______
  of the universe.
• Based on data from the ___________ Space
  Telescope and the data on the cosmic background
  _____________, the age of the universe can be
  hypothesized to be __________ billion years.

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Big Bang Model

• Based on the Big Bang theory, there are three
  possible outcomes for the universe.
• The universe could be an ___________ universe and
  ___________ to expand forever.

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Possible Outcomes

1. The universe could be a _________ universe where
   the expansion ________ and all of the mass is
   pulled _________ to the original point of origin
2. or it could be a _______ universe where the
   expansion becomes so slow that it seems to
   __________.

Closed universe
Flat universe
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Critical Density

• All three outcomes are based on the premise that
  the _________ of expansion has ______________
  since the beginning of the universe, but the
  ___________ of the universe is what is unknown.

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Cosmic Background Radiation

• In 1965, scientists discovered a persistent
  background ___________ in their _____________
  antenna.
• Persistent background noise was caused by weak
  ______________, called the cosmic background
  radiation, that appeared to come from ________
  directions of space and corresponded to an
  emitting object having a temperature of about
  ___________ (270?C).

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Cosmic Background Radiation

• The temperature was _____________ to the
  temperature predicted by the Big Bang theory, and
  the radiation was interpreted to be from the
  beginning of the Big Bang.
• Earths _________________ blocks much of the
  cosmic background radiation, so it is best
  observed from high-altitude ________________ or
  satellites.
• An orbiting observatory called the Wilkinson
  Microwave Anisotropy Probe (WMAP), launched by
  NASA in 2001, mapped the radiation in greater
  detail.