Download Then another Big Bang will occur and the

THE BIG BANG THEORY
STATES THAT THE UNIVERSE
BEGAN AS A SINGLE COSMIC
EXPLOSION ABOUT 15 BILLION
YEARS AGO.
Who?
 In 1964, Penzias and
Wilson discovered the
remnant heat of the Big
Bang. This is called
cosmic microwave
background radiation. It
is all around us.
 The radiation corresponds
to a temperature of 3
degrees above absolute zero
(- 454 F).
Infrared Radiation
An animal, or a
human body, for
example, emits
some infrared
radiation that can
be detected by an
infrared camera
The COBE Satellite
(Cosmic Background explorer)
 Before correction of the
Earth movement around the
Sun
 Before correction of the
microwave radiation emitted
by our own galaxy
 The final image of the
microwave radiation
Background Radiation
 Energy left over from the Big Bang
that is evenly spread out
throughout the universe.
 This background radiation is one
observation that supports the Big Bang
Theory.
And then a better picture!
The WMAP
satellite gave a
better
resolution of
the small
fluctuations of
temperature
WMAP Data
So, the big-bang must have taken place
at the same time everywhere.
But we can also observe small
fluctuations of temperature which may
have lead to the formation of the
galaxies.
Small fluctuations compared to those at the
surface of the Earth
After the Big Bang
 Gravity began to affect matter racing
in every direction.
 The clumps formed into huge clusters
of matter.
 These clumps became the galaxies of
the universe.
The Race is On!!
 Every galaxy seems to be moving away
from Earth.
 After examining the Red Shift that appears
from distant galaxies astronomers conclude
the universe is expanding at tremendous
speeds.
What is red shift?
In order to understand Red
Shift we must first look at the
Doppler Effect.
http://www.youtube.com/wa
tch?v=z0EaoilzgGE
The Doppler Effect
Whenever a source of sound is moving, the pitch you hear depends on whether the sound source
is moving towards you or away from you.
Light Travels in the same way:
 As objects move towards the Earth they emit a Blue
light called the Blue Shift.
 As objects move away from the Earth they emit a Red
Light called the Red Shift.
 This was seen using the Hubble Telescope.
Distance between Stars
 Fortunately for us, the average
distance
between stars is about 3 light years or 20
trillion miles.
 If stars were 10 times closer (~2 trillion miles), a nearby
star could pull the earth into an eccentric orbit and kill
life here.
 If the stars were much farther apart, then there would
not be enough heavy elements to make life. Heavy
elements (like carbon and oxygen) are
the ashes of dead stars and living things
(including us) need these elements.
Expanding Universe
 If the universe is expanding, then
the objects near the very edge of
the universe are the oldest objects
in the universe.
 The most distant known objects in
the universe are over 12 billion
light years from the Earth
Three Pieces of Evidence Supporting the Big
Bang
 The presence of Background
Radiation
 The observation of the galaxies
spreading away from the center of
the universe (Red Shift)
 Elements presence
What Happens Next?
 Astronomers feel that the Big
Bang theory leads to two
possible futures for the
Universe.
Open Universe
 Galaxies will continue racing outward
(continue to expand). All of the stars
will die off as the last of their energy is
released. There will be nothing left,
total emptiness.
Closed Universe
 Gravitational attraction between the
galaxies will cause the movement
away from each other to slow and,
eventually come to a halt.
 The gravitational pull will begin to
pull the galaxies back to the center of
the universe.
Closed Universe cont.
 All of the matter and energy will again
come close together and end in a
central area (possibly no larger than a
dime).
 Then another Big Bang will occur and
the formation of the universe will
begin all over again.
Um… I think we may have been here before?
 This restructuring may occur once
every 80 to 100 billion years.