Theories explaining the origin of the universe.

4. In the Bible, there was time when
the world did not exist. Only God
existed. He decided to create the world
and with that decision, the world began.
the universe is everything that
exists. All the planets, stars, and
galaxies are part of the universe, and so,
is all of space.
Cosmology is the study of universe.

5. Theories on the Origin of the
Universe
1. Big Bang Theory
Most astronomers believe that the
universe began about 15 billion years ago, in a
huge explosion they called the Big Bang. This
theory successfully explains the expansion of
the universe and the observed abundance of
helium in the universe.
• First developed in 1927 by Georges Lemaitre
(1984-1966)
• and coined and revised by George Gamow
(1904-1968)

6. Georges Lemaitre George Gamow

11. Theories on the Origin of the
Universe
2. Open Universe
Edwin Hubble (1889-1953) discovered the
galaxies of the universe are moving farther apart.
This means that the universe is getting continually
bigger or getting bigger forever.
Alternatively, the galaxies may come together,
until finally they will collide and explode. This event is
called the “Big Crunch”.
If the Big Crunch occurred, the sky would
grow as hot as the sun. Finally, everything would
vanish into a blackhole.

16. Theories on the Origin of the
Universe
3. Steady State
Proposed by Hermann Bondi, Thomas Gold, and
Fred Hoyle in 1928, this suggests that there is neither
beginning nor end to the universe, and it has a
constant mean density.
This theory postulates that matter is created
throughout the universe at a rate of about 10-10
nucleon per meter cube per year as a property of
space.
this violates the Law of Conservation of
Matter and Energy.

17. Hermann Bondi
Fred Hoyle
Thomas Gold