The Origin of
the Universe
Reminders:
• Turn on your video and mute your
microphone.
• Use of chat box to address your questions
or clarifications.
Objective:
• Describe the different hypothesis explaining the origin
of the universe
Astronomy
is the scientific study of
celestial objects (such as stars,
planets, comets, and galaxies)
and phenomena that originate
outside the Earth's atmosphere
(such
as
the
cosmic
background radiation).
Astrology
the study of the movements and relative positions
of celestial bodies interpreted as having an influence on
human affairs and the natural world.
Cosmology
the science of the
origin and development of
the universe.
• It is difficult to completely understand the formation of
the universe because no human has ever witnessed
it.
• The science of cosmology provides various
hypotheses that explain the origins of the universe
based on its present properties or characteristics.
• It should be likewise be noted that advances in
scientific tools and instruments continuously help
validate theories.
The Big bang Theory
• The Big bang Theory remains to be prevailing
cosmological model of the early development of the
universe. It provides the best explanation of the
origin of the universe and is implicitly accepted.
• According to the Big bang
Theory, the universe was
once very small and very hot,
and then it expanded over
time until it reached its peak
(which may perceived as a
massive explosion for some)
around 13.7 billion years ago
(considered the age of the
universe)
• The Big bang model also asserts that
seconds after the explosion, the
surrounding were at high temperature
of about 10 billion degrees Fahrenheit
or 5.5 billion Celsius with aggregates
of fundamental particles such as
neutrons, electrons, and protons.
• As the universe cooled in later
phases,
these
particles
either
combine with each other or decayed.
Steady State Theory
• This theory states that the universe is always expanding in a
constant average density. Because of this state, matter
continuously created to form cosmic or celestial bodies such
as stars and galaxies.
• The older bodies that were formed are no longer easily
absorbable as a consequence of their huge distances rate of
recession.
• This theory further claims that the
universe has no beginning or end
in time, and even though it is
expanding, its appearance remains
the same over time.
• The steady state theory was first
proposed by Sir James Jeans (18771946) in 1920. It gained popularity
after it was revised by Fred Hoyle
(1915-2001), Hermann Bondi (19192005), and Thomas Gold (19202004) in 1948 as an alternative for
Big bang theory.
•
•
•
However, toward the 1960s,
much evidences was produced
that
would
contradict
the
steadiness or the unchanging
state of the universe.
When certain galactic bodies
such as quasar and radio
galaxies were found only at far
distances in space, it just
disprove the idea that similar
bodies are created and found
everywhere.
This implies that the universe is
actually evolving and not steady.
Cosmic Inflation Theory
• The
most
recent
cosmic theory was
proposed by physicist
Alan
Guth
(1947present)
and Andrei
Linde (1948-present) in
the 1980s.
• The term inflation refers
to the rapid expansion
of space-time.
• According to this theory, the early universe was rapidly
expanding bubble of pure vacuum energy. It did not have any
matter or radiation. After the expansion, and cooling arising
from this inflation, the potential energy converted into kinetic
energy of matter and radiation. Then Big bang occurred
because of the extremely hot, dense condition of matter.
The cosmic inflation theory became an
accepted hypothesis because it answer
many “puzzling” observation that arose in the
Big bang theory.
st
1
Puzzling Observation
• The
homogeneity
of
objects in space.
• During
the
expansion
period, objects that usually
in contact got farther away
from one another.
• Their
composition,
however, remained almost
intact.
nd
2
Puzzling Observation
• The observation about the universe is its appearance
of flatness or smoothness. The continuous expansion
dilutes or gradually loses the curvature of objects.
rd
3
•
•
•
Puzzling Observation
It has something to do with the formation
of the stars and star system in later years.
This theory asserts that during expansion,
small density fluctuations happen. This
causes gravity to attract gas into masses,
giving birth to stars and eventually
galaxies.
This also explains why the universe would
always look full of planetary objects
instead of appearing completely empty.
ORIGIN OF
THE
UNIVERSE
BIG BANG
THEORY
STEADY STATE
THEORY
COSMIC INFALTION
THEORY