A Static Universe In the early 1900s, the accepted view held
was that the universe was static, which never changes; it has
always been the same and always will Albert Einstein was one of the
largest supporters of this belief When the idea of an expanding
universe was proposed, Einstein spoke out: This circumstance
irritates me. To admit such possibilities seems senseless.
Slide 4
Hubbles Discoveries However, not everyone was convinced that
the universe was never changing In 1929, astronomer Edwin Hubble,
at the Mt. Wilson Observatory in California, found that the
velocity of a star appeared to be proportional to its distance from
the Earth The further the star from the Earth, the faster it
appeared to move away from the Earth This concluded that the
universe is expanding and the galaxies are moving away at high
speeds
Slide 5
Einsteins Mistake Looking to gain a greater understanding of
the universe, Einstein turned to his theory of general relativity-
the current description of gravitation in physics His surprising
discovery found that the universe would have to be expanding and
contracting Hubbles findings, paired with Einsteins theory
supported the idea of an expanding universe
Slide 6
Georges Lemaitre Georges Lemaitre was a Belgian Cosmologist and
Catholic priest Used Einsteins laws of gravitation as a basis to
claim that the universe must be expanding He published a solution
to equations of general relativity in 1927 in regards to the
expanding universe Stated that the expanding universe was not
static but without evidence he had little support His model soon
became known as the Big Bang Theory
Slide 7
The Big Bang Theory Combination of two approaches to the
universe: astronomical and cosmological Describes the development
of the universe prior to its current existence All matter and space
in the universe was originally compressed into a tiny dot, called
the singularity, which expanded and all the matter instantly filled
what is now our universe
Slide 8
Evidence for the Big Bang Lemaitre used Hubbles findings to
support his theory If the galaxies are currently moving forward, at
one point they must have been all together Once there was a
primordial atom that contained all the matter in the universe
Lemaitre also used the concept of entropy - everything is moving
towards greater disorder to support his theory
Slide 9
Following the Discovery Much debate followed his theory - some
supported the idea while others chose to take on a steady state
theory The universe is constantly expanding, but the average
density remains constant Debate ended when Arno Penzias and Robert
Wilson found evidence for cosmic background radiation residue of
the big bang The expansion of the universe is now viewed as one of
the greatest scientific discoveries
Slide 10
Impact of the Big Bang Theory The Big Bang Theory sparked
discussion and encouraged further studied into the universe This
theory is used as a way to estimate the age of the universe (within
a large range) It also lead to questions relating to the universe
expansion Will it expand forever? What happened before the big
bang?
Slide 11
Never in all the history of science has there been a period
when new theories and hypotheses arose, flourished, and were
abandoned in so quick succession as in the last fifteen or twenty
years. Willem de Sitter, 1931
Slide 12
References Big Bang Theory is Introduced. (n.d.). PBS.
Retrieved February 26, 2014, from
http://www.pbs.org/wgbh/aso/databank/entries/dp27bi.htmlhttp://www.pbs.org/wgbh/aso/databank/entries/dp27bi.html
Georges Lemaitre, Father of the Big Bang. (n.d.). Georges Lemaitre,
Father of the Big Bang. Retrieved February 26, 2014, from
http://www.amnh.org/education/resources/rfl/web/essaybooks/cosmic/p
_lemaitre.html
http://www.amnh.org/education/resources/rfl/web/essaybooks/cosmic/p
_lemaitre.html Strickland, J. (2008, June 18). How the Big Bang
Theory Works. HowStuffWorks. Retrieved February 25, 2014, from
http://science.howstuffworks.com/dictionary/astronomy-terms/big-bang-
theory.htm
http://science.howstuffworks.com/dictionary/astronomy-terms/big-bang-
theory.htm The Expanding Universe (Cosmology: Ideas). (n.d.). The
Expanding Universe (Cosmology: Ideas). Retrieved February 26, 2014,
from http://www.aip.org/history/cosmology/ideas/expanding.htm
http://www.aip.org/history/cosmology/ideas/expanding.htm