3. Titles :
• Introduction to 'The Big Bang' (TBB)
and 'The Big Bang Theory' (TBBT)
• Explanation of 'The Big Bang'
• Age of the universe
• The universe started with a huge explosion 13
billion years ago. This explosion is called 'The
• The Big Bang theory is basically an effort to
explain what happened at the very beginning
of our universe.
• The Big Bang theory says that, "The universe
started with a cataclysm that created space
and time and all the matter and energy that
has ever existed in the universe.
5. • Georges Lemaitre was the first person
to propose what became the Big Bang
theory through his 'Hypothesis of the
• Scientists later built on his ideas to
form the modern theory of the big
7. • 12-14 billion years ago, the universe was hot,
dense and only few mm across.
• The universe was created by a huge explosion,
known as the big bang.
• Prior to the moment when the universe began
there was nothing, during and after that
moment , there was something. "Our Universe".
TBBT explains what happened during & after
8. • After TBB occured, the universe was in
an extremely hot and dense state and
began expanding rapidly.
• The first electrically neutral atoms
appeared thousands of years later. The
first elements were hydrogen & small
quantity of helium and lithium.
• 400 millions years after TBB, stars and
galaxies were formed by combination of
clouds of elements.
9. • Higher elements were formed either
within the stars or during supernova and
formed new stars and planets.
• 380,000 years after the big bang, the
temperature of universe cooled down to
the current temperature.
• It has since expanded to a vast and much
cooler cosmos and it continues to expand
and cool to this day.
12. There are at least three ways that
the age of universe can be
The age of the chemical elements.
The age of the oldest star clusters.
The age of the oldest white dwarf star.
13. →Edwin Hubble -Hubble's law
→Galaxies appeared to be moving
away from us at speed proportional
to their distance.
→By using Hubble's law and by
working backward scientists can
determine approximately how old
the universe is.
14. • In physical cosmology , the age of the
universe is the time elapsed since the
Big Bang. The current measurement of
the age of the universe is 13.798±0.037
• The uncertainty of 37 million years has
been obtained by the agreement of a
number of scientific research projects.