ThursdayAugust 30, 2012

(The Big Bang Theory and General Relativity; The Doppler Effect and

Red Shift)

The Launch PadThursday, 8/30/12

Which of the following best describes the Big Bang Theory?

A. The Universe has always existed as it is today, and always will.

B. Matter and energy suddenly exploded into already existing space

and time.C. Time, space, matter, and energy all

came into being at the same time and something was created from

nothing.D. 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.

Assignment Currently Open

Summative or

Formative?Date Issued Date Due Date Into

GradeSpeed Final Day

ESS Class Information Sheet F 8/27 8/28

ESS Class Procedures and

ExpectationsF 8/27 8/29

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.

Recent Events in Science

The Big Bang TheoryThe 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.

The Doppler Effect