WednesdayAugust 31, 2011 (Supporting the Big Band Theory; the Doppler Effect; Red and Blue Shifts)
The Launch Pad Wednesday, 8/31/11 Explain how Albert Einstein changed our understanding of Isaac Newton's idea of gravity.
Latest News A private U.S. rocket company building robotic spaceships to carry space station supplies for NASA has delivered the first of its cargo ships to its launch site in Virginia. The company Orbital Sciences Corp. delivered the first cargo module for its Cygnus spacecraft fleet to NASA's Wallops Flight Facility on Wallops Island, Va., on Aug. 23 to prepare for a test flight to the International Space Station in February.
The Big Bang Theory • The framework for the model relies on Albert Einstein's Theory of General Relativity. • http://www.youtube.com/watch?v=tpbGuuGosAY • 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.