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Thursday August 30, 2012. (The Big Bang Theory and General Relativity; The Doppler Effect and Red Shift). The Launch Pad Thursday, 8/30/12. Which of the following best describes the Big Bang Theory?. The Universe has always existed as it is today, and always will.
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ThursdayAugust 30, 2012 (The Big Bang Theory and General Relativity; The Doppler Effect and Red Shift)
The Launch Pad Thursday, 8/30/12 Which of the following best describes the Big Bang Theory? The Universe has always existed as it is today, and always will. Matter and energy suddenly exploded into already existing space and time. Time, space, matter, and energy all came into being at the same time and something was created from nothing. Matter and energy cannot be created nor destroyed.
Announcements • Please remember that we will have our first Quiz tomorrow. • All serious ESS students should now be in possession of a science journal.
Recent Events in Science There's a rare `blue moon' tomorrow, a fitting tribute to Neil Armstrong by the cosmic calendar. That's the day of a private service for Armstrong, the first man to walk on the moon, who died last Saturday in Ohio at age 82. A blue moon occurs when there's a second full moon in one calendar month. It won't happen again until July 2015. The full moon cycle is 29.5 days so a blue moon is uncommon and has come to mean something rare. The moon actually won't be colored blue. Armstrong's family has suggested paying tribute to him by looking at the moon and giving the astronaut a wink.
The Big Bang Theory • The Big Bang model, or theory, is the prevailing cosmological theory of the early development of the universe, and attempts to explain some of the earliest events in the universe. • According to the theory, the universe was once in an extremely hot and dense state that expanded rapidly (a "Big Bang"). • As there is little consensus among physicists about the origins of the universe, the Big Bang theory explains only that such a rapid expansion caused the young universe to cool and resulted in its present continuously expanding state. • According to recent measurements, the original state of the universe existed around 13.8 billion years ago, to which some physicists refer as the time that the Big Bang occurred. • Physicists have attempted to establish the theory's validity through scientific evidence and observations.
The Big Bang Theory • The framework for the model relies on Albert Einstein's Theory of General Relativity. • http://www.youtube.com/watch?v=30KfPtHec4s • General relativity is a geometrical theory of gravity developed by Einstein in which gravity's effects are a consequence of the curvature of four-dimensional “space-time.” • According to this theory, the energy and momentum of all matter and radiation cause curvature in space-time.
The Big Bang Theory • This curvature also opens the possibility that the universe is closed, having finite volume but without any boundary. • Among the many experimentally confirmed consequences of general relativity are the perihelion precession of the planet Mercury, the bending of light in a gravitational field, and the slowing of time in a gravitational field.
The Big Bang Theory • In 1929,Edwin Hubble discovered that the distances to far away galaxies were generally proportional to their redshifts. • http://www.youtube.com/watch?v=FhfnqboacV0 • Hubble's observation was taken to indicate that all very distant galaxies and clusters have an apparent velocity directly away from our vantage point: the farther away, the higher the apparent velocity.
The Doppler Effect • The Doppler Effect is the apparent change in frequency of waves (pitch) due to the motion of the source or observer. • Note: The higher the frequency the higher the pitch. • A great example is an ambulance’s siren coming toward you and then passing you. The pitch drops as the ambulance passes.
