3. Titles :
• Introduction to 'The Big Bang' (TBB)
and 'The Big Bang Theory' (TBBT)
• Explanation of 'The Big Bang'
• Age of the universe
4. Introduction
• The universe started with a huge explosion 13
billion years ago. This explosion is called 'The
Big Bang'.
• 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
primeval atom'
• Scientists later built on his ideas to
form the modern theory of the big
bang.
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
that moment.
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
estimated:
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
billion years
• The uncertainty of 37 million years has
been obtained by the agreement of a
number of scientific research projects.