this ppt is based on Big Bang

1. Presented By:
S Mansi Pillai

2. FOUNDATIONS OF BIG BANG THEORY
Edwin Hubble Aleksandr
Friedmann (expansion of universe)
(explanation of
general relativity)
Georges Lemaître
(origin of space from single point)

3. THE BIG BANG – a day without yesterday
 Is the leading explanation of our
Universe’s origin.
 It states that Cosmos started with a single
point of hot and dense state.
 Expansion is the key concept of the
theory.

4. MISCONCEPTIONS ABOUT THE THEORY
o The big bang did not occur as a point of
‘explosion’.
o The theory does not deal with what is
outside the Universe or what it is expanding
into.
o It also does not deals with what actually
gave rise to the big bang.

5. EVIDENCES FOR BIG BANG THEORY
 There are no experiments we can
conduct on the big bang theory as it
occurred long back.
 Therefore most evidences are in form of
observations.
 The earliest and the most direct
evidences are as follows :-

6. 1. DOPPLER EFFECT
 First given Christian Johann Doppler
 States that:
 If light waves emitted by an object are
contracted then, it is moving closer.
 If light waves are extended then, the object is
moving away.
 Used by Hubble to calculate the
speed of the receding galaxies.

7. 2. BIG BANG NUCLEOSYNTHESIS (BBN)
o First put by George Gamow.
o States that due to intense heat of big bang
elements could be created by adding more
particles to the hydrogen atom.
o Verified the origin of elements up
to mass 5 and 8 amu.

8. 3. COSMIC MICROWAVE BACKGROUND (CMB)
 Also proposed by Georges Gamow.
 Idea behind:
 The residual heat from big bang is still trekking
around the Universe.
 In 1965, Aron Penzias and Robert Wilson noticed
Gamow’s microwave background which confirmed
big bang significantly.

9.  In 1989, NASA’s COBE further confirmed Gamow’s
theory.
 Launched in 2001, WMAP satellite yielded the CMB
revealing the images of our Universe just 380,000
years old.

10. THANK YOU