Contents The Big Bang Theory The Big Bang Phase Expanding Universe Testing Big Bang Model Dark matter & Dark energy Evidence of dark matter After time period of Big Bang Life cycle of star

2. Group Name: Back Bencher
Group Members
S M Manna (14203083)
Sumon Kumar Ghosh (14203098)
Imam Uddin (14203071)
MD. Sayham Khan (14203123)
MD. Yousuf Hassan (14203100)
Presentation Day: 12 March 2015
2The Big Bang

3. Contents
• The Big Bang Theory
• The Big Bang Phase
• Expanding Universe
• Testing Big Bang Model
• Dark matter & Dark energy
• Evidence of dark matter
• After time period of Big Bang
• Life cycle of star
The Big Bang 3

4. The Big Bang
• The universe begins
~13.7 Billion years ago
• The universe begins as
the size of a single atom
• The universe began as a
violent expansion
– All matter and space
were created from a
single point of pure
energy in an instant.
Image 1: Beginning of Big Bang
4The Big Bang

5. The Big Bang: Phase
Phase 1
At the beginning of time, from
Complete nothingness, a cosmic
Explosion ignites.
Phase 2
The thrust from the explosion sends
Billions of tons of energy through space
And the elements begin to cool.
Image 2: Phase 1
Image 3: Phase 2
5The Big Bang

6. The Big Bang: Phase
Phase 3
Galaxies begin to take shape while
Still moving away from the initial
Point of ignition.
Phase 4
The universe continues to expand to
This very day.
Image 4: Phase 3
Image 5: Phase 4
6The Big Bang

7. Ever Expanding Universe
According to the
Big Bang model,
the
universe expande
d from an
extremely dense
and hot state and
continues to
expand today.
Image 6: Ever Expanding Universe
7The Big Bang

8. Testing the Big Bang model
• Prediction: If the universe was denser, hotter, in
past, we should see evidence of left-over heat
from early universe.
• Observation: Left-over heat from the early
universe. (Penzias and Wilson, 1965)
Image 7: Left over heat from early universe
8The Big Bang

9. Testing the Big Bang model
• Prediction: A hot, dense expanding universe,
should be predominantly hydrogen, helium.
• Observation: Universe is ~75% hydrogen,
~25% helium by mass
Image 8: The Sun: 74.5% H, 24% He by mass
Image 9: Cecilia Payne
9The Big Bang

10. Testing the Big Bang model
• Observation: 90% of matter is an
unknown form: Dark Matter.
• Refine: A new and unknown form of
matter exists. But its gravity
• works the same way, and its presence is
needed to explain how the universe looks.
Image 11: Vera Rubin
Image 10: Testing Big Bang
10The Big Bang

11. Expansion is accelerating
A recent discovery
and of unknown
origin, the concept of
Dark Energy is
actually an integral
part of Einstein’s
theory of gravity.
Image 12: Science Magazine
11The Big Bang

12. Dark Energy
73%
Normal Matter
4%
Dark Matter
23%
Figure 1: Materials of Universe 12The Big Bang

13. Evidence for Dark Energy -
supernovae as distance
indicators - step 1
Image 12: A dying star becomes a white dwarf.
13The Big Bang

14. Evidence for Dark Energy -
supernovae as distance
indicators - step 2
Image 13: The white dwarf strips gas from
its stellar companion….
14The Big Bang

15. Evidence for Dark Energy -
supernovae as distance
indicators - step 3
Image 14: ….and uses it to become a hydrogen bomb. Bang!
15The Big Bang

16. Evidence for Dark Energy -
supernovae as distance
indicators - step 4
Image 15: The explosion is as bright as an entire galaxy of stars….
16The Big Bang

17. Evidence for Dark Energy -
supernovae as distance
indicators - step 5
Image 16: and can be seen in galaxies across the universe.
17The Big Bang

18. How Everything Began
~ Several hundred thousand years
after Big Bang
• ATOMS form
(specifically
Hydrogen and its
isotopes with a small
amount of Helium.)
• The early Universe
was about 75%
Hydrogen and 25%
Helium. It is still
almost the same
today.
Figure 2: Atom Formation.
18The Big Bang

19. ~200 to 400 million years after Big Bang
• 1st stars and
galaxies
form
Image 17: ~200 to 400 million years after Big Bang
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20. ~ 4.6 billion years ago
• Our Solar
system
forms
Image 18: Our Solar system forms
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21. Misconceptions about the Big Bang
• there was no explosion; there was (and continues to be)
an expansion
– Rather than imagining a balloon popping and
releasing its contents, imagine a balloon expanding:
an infinitesimally small balloon expanding to the size
of our current universe
• we tend to image the singularity as a little fireball
appearing somewhere in space
– space began inside of the singularity. Prior to the
singularity, nothing existed, not space, time, matter, or
energy - nothing.
21The Big Bang

22. Figure 3: Life cycle of a star
22The Big Bang

23. Big Bang evidence
1) Universal expansion and Hubble’s Law
2) 3 degree background radiation
3) Quasars
4) Radioactive decay
5) Stellar formation and evolution
6) Speed of light and stellar distances
23The Big Bang

24. Conclusions – Till Now
• Big Bang model describes our current
understanding of the universe.
• New discoveries, such as dark matter and
accelerating expansion (Dark Energy), lead
us to refine our model,
but there is no crisis in our understanding
(yet).
• Science is an ongoing process - forcing us to
test our model through prediction and
observation.
• The more tests it passes, the greater is our
confidence in it.
24The Big Bang

25. The Future of Cosmology:
Beyond Einstein
• What powered the Big Bang?
• What Is Dark Energy?
• How did the Universe begin?
25The Big Bang

26. LASTLY – we are pretty sure everything
has a beginning, right?
Image 20: Funny picture about Big Bang
26The Big Bang

27. Thanks
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