The Big Bang Theory is the leading explanation about how the universe began approximately 13.8 billion years ago from a small singularity. It has been developed over hundreds of years, with key contributors including Kepler, Darwin, Hubble and Lemaitre. Evidence that supports the theory includes the cosmic microwave background radiation, which is the echo of the expansion; the redshifting of galaxies moving away from us at speeds proportional to their distance; and the relative abundances of light elements like hydrogen and helium. While the Big Bang Theory is currently the prevailing cosmological model, some alternatives have been proposed like eternal inflation and the steady state theory.

1. By :Maria Jose Heredia Reyes,Martha Munzón Ayora y Julia
Moran Perez

2. BIG BANG•According cosmological principle, distance from the galaxies suggested
that the universe expanding.
•The Big Bang Theory is the leading explanation about how the universe
began.
•As we know it started with a small singularity, increased over the next 13.8
billion years to the cosmos that we know today.
•Much of what we understand, comes from mathematical formulas and
models.
•Astronomers can, see the echo of the expansion through a phenomenon
known as the cosmic microwave background.

4. HISTORY OF THE
DEVELOPMENT OF THEORY

5.  In medieval
philosophy
 1610, Johannes
Kepler
 1791 - Erasmus
Darwin
 1910s, Vesto
Slipher- Carl
Wilhelm Wirtz

6.  1922-Alexander
Friedmann
 1927, Georges
Lemaître
 1929, Edwin
Hubble

7. ◼1950 to 1965- the support for these theories
was evenly divided
◼1960s
◼1990
◼1998

8. Evidence for the Theory
Cosmic Microwave
Background Credit
The major evidences that support the Big Bang
are
● First of all, we are reasonably certain that the
universe had a beginning.
● Second, galaxies appear to be moving away
from us at speeds proportional to their
distance.
● Third, if the universe was initially very, very
hot as the Big Bang suggests, we should be
able to find some remnant of this heat.
● Finally, the abundance of the "light elements"

9. IS IT THE ONLY THEORY?
 No, there are more
theories.
 Eternal Inflation
 Steady State

10. FACTS
 1) Hubble's discovery of the expanding Universe turned it
into a serious idea.
- 1920s
- + distant galaxy was, faster was receding away from us
 2)The name "Big Bang" came about from the theory's
Fred Hoyle.
- 1949 speaking to the BBC. The Universe started its life a
finite time ago in a huge explosion.
 3)The confirmation of the Big Bang gives us an explicit
history for the formation of stars, galaxies, and rocky
planets in the Universe.
- 1st stars 50 to 100 million years to form.
- Milky Way-sized galaxies might take billions of years.

11. FACTS
◼ 4) We cannot know what came before the Big Bang:Space
and time came into existence at the same moment so there
was no ‘before the Big Bang
◼ 5) The Solar System formed about 9 billion years after the
Big Bang :The Sun is therefore a late generation star that
contains the debris from many generations of stars that have
gone before.
◼ 6) 90 percent of the universe may be made up from dark
matter and dark energy:There are certain things about our
universe that can’t be explained without the existence of the
‘dark matter’ and ‘dark energy’.

12. THANK YOU FOR YOUR ATTENTION