2. 2
The Big Bang is a
titanic explosion that
created energy, matter,
space and time.
Between 13-15 billion
years ago.
3. Discoveries in astronomy have shown
beyond a reasonable doubt that our
universe did have a beginning: It all
started with an explosion known as the
Big Bang
The Big Bang theory generally refers to
the idea that this universe has
expanded from a very hot and dense
initial condition at some time in the
past, and it continues to expand. 3
4. The Big Bang theory is basically an
effort to explain what happened at
the very beginning of our universe.
Prior to the moment when the universe
began, there was nothing; during and
after that moment there was
something: our universe. The big bang
theory explains what happened during
and after that moment.
4
5. 5
Gravity began to affect matter racing in
every direction.
After the initial expansion, the Universe
cooled enough to allow energy to be converted
into various subatomic particles, including
protons, neutrons and electrons.
These clumps became the galaxies of the
universe.
8. 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.
9. Describe how light changes as objects
in space such as (star or galaxies)
move farther away from each other
The greater the redshift, the greater the
galaxy’s speed.
9
10. 10
There are three different theories of what will
happen with our universe and how it expands.
•The Big Crunch
•Continuing Forever
•The Big Chill
11. The Big Crunch is a situation that
scientists predict will happen. The Big
Crunch explains how the universe will
end. The theory states that the universe
will not continue to expand forever.
Eventually the expansion of the universe
will stop and the universe will collapse on
itself forming a gigantic black hole.
11
13. If the universe is less dense than the
"critical density" then it will continue to
expand forever. If the universe is more
dense than the "critical density" then the
universe will collapse on itself which is
called the Big Crunch.
The "critical density" is 10^-30 grams per
cubic centimeter 13
14. The Big Chill is a theory that states the
universe will continue expanding and
eventually run down to a state of zero
energy. The temperatures will reach very
close to absolute zero where the only
remaining things would be burnt out
stars, cold dead planets, and black holes.
14
15. History & Development
- Einstein (1879–1955)
15
Einstein predicted that
the universe is
expanding and he
came up with 10 field
equations to support
his general theory of
relativity.
16. History & Development
- Alexander Friedmann (1888-1925)
16
Alexander
Friedmann, a
Russian cosmologist
and mathematician,
read Einstein’s work
but thought that the
cosmological
constant was wrong
18. 1. We are sure that the universe had a
beginning.
2. Galaxies appear to be moving away from us
at speeds proportional to their distance; this
is called ‘Hubble’s Law’
3. If the universe was initially very hot, we
should be able to find some remnant of the
heat (Cosmic Microwave Background
radiation).
4. The abundance of light elements, hydrogen
and helium found in the observable universe.
18Big Bang Theory