WednesdayAugust 31, 2011

(Supporting the Big Band Theory; the Doppler Effect; Red and Blue

Shifts)

The Launch PadWednesday, 8/31/11

Explain how Albert Einstein changed our

understanding of Isaac Newton's idea of gravity.

Assignment Currently Open Page Date of Notes on Website Date Issued Date Due

ESS Class Information Sheet N/A N/A 8/24 8/25

Class Procedures and Expectations TBD 8/24 8/24 8/26

Lab - Stretching the Fabric of Space TBD 8/29 8/29 8/30

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 TheoryThis 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.

The Doppler Effect