The Big Bang Model vs. The Steady State


It is always a mystery about how the universe began, as
well as if and when it will end. Astronomers construct
hypotheses called cosmological models that try to find the
answer. There are two types of models: Big Bang and Steady
State. However, through many observational evidences, the
Big Bang theory can best explain the creation of the
The Big Bang model postulates that about 15 to 20 billion
years ago, the universe violently exploded into being, in
an event called the Big Bang. Before the Big Bang, all of
the matter and radiation of our present universe were
packed together in the primeval fireball--an extremely hot
dense state from which the universe rapidly expanded.1. The
Big Bang was the start of time and space. The matter and
radiation of that early stage rapidly expanded and cooled.
Several million years later, it condensed into galaxies.
The universe has continued to expand, and the galaxies have
continued moving away from each other ever since. Today the
universe is still expanding, as astronomers have observed.
The Steady State model says that the universe does not
evolve or change in time. There was no beginning in the
past, nor will there be change in the future. This model
assumes the perfect cosmological principle. This principle
says that the universe is the same everywhere on the large
scale, at all times.2. It maintains the same average
density of matter forever.
There are observational evidences found that can prove the
Big Bang model is more reasonable than the Steady State
model. First, the redshifts of distant galaxies. Redshift
is a Doppler effect which states that if a galaxy is moving
away, the spectral line of that galaxy observed will have a
shift to the red end. The faster the galaxy moves, the more
shift it has. If the galaxy is moving closer, the spectral
line will show a blue shift. If the galaxy is not moving,
there is no shift at all. However, as astronomers observed,
the more distance a galaxy is located from Earth, the more
redshift it shows on the spectrum. This means the further a
galaxy is, the faster it moves. Therefore, the universe is
expanding, and the Big Bang model seems more reasonable
than the Steady State model.
The second observational evidence is the radiation produced
by the Big Bang. The Big Bang model predicts that the
universe should still be filled with a small remnant of
radiation left over from the original violent explosion of
the primeval fireball in the past. The primeval fireball
would have sent strong shortwave radiation in all
directions into space. In time, that radiation would spread
out, cool, and fill the expanding universe uniformly. By
now it would strike Earth as microwave radiation. In 1965
physicists Arno Penzias and Robert Wilson detected
microwave radiation coming equally from all directions in
the sky, day and night, all year.3 And so it appears that
astronomers have detected the fireball radiation that was
produced by the Big Bang. This casts serious doubt on the
Steady State model. The Steady State could not explain the
existence of this radiation, so the model cannot best
explain the beginning of the universe.
Since the Big Bang model is the better model, the existence
and the future of the universe can also be explained.
Around 15 to 20 billion years ago, time began. The points
that were to become the universe exploded in the primeval
fireball called the Big Bang. The exact nature of this
explosion may never be known. However, recent theoretical
breakthroughs, based on the principles of quantum theory,
have suggested that space, and the matter within it, masks
an infinitesimal realm of utter chaos, where events happen
randomly, in a state called quantum weirdness.4
Before the universe began, this chaos was all there was. At
some time, a portion of this randomness happened to form a
bubble, with a temperature in excess of 10 to the power of
34 degrees Kelvin. Being that hot, naturally it expanded.
For an extremely brief and short period, billionths of
billionths of a second, it inflated. At the end of the
period of inflation, the universe may have a diameter of a
few centimeters. The temperature had cooled enough for
particles of matter and antimatter to form, and they
instantly destroy each other, producing fire and a thin
haze of matter-apparently because slightly more matter than
antimatter was formed.5 The fireball, and the smoke of its
burning, was the universe at an age of trillionth of a
The temperature of the expanding fireball dropped rapidly,
cooling to a few billion degrees in few minutes. Matter
continued to condense out of energy, first protons and
neutrons, then electrons, and finally neutrinos. After
about an hour, the temperature had dropped below a billion
degrees, and protons and neutrons combined and formed
hydrogen, deuterium, helium. In a billion years, this cloud
of energy, atoms, and neutrinos had cooled enough for
galaxies to form. The expanding cloud cooled still further
until today, its temperature is a couple of degrees above
absolute zero.
In the future, the universe may end up in two possible
situations. From the initial Big Bang, the universe
attained a speed of expansion. If that speed is greater
than the universe's own escape velocity, then the universe
will not stop its expansion. Such a universe is said to be
open. If the velocity of expansion is slower than the
escape velocity, the universe will eventually reach the
limit of its outward thrust, just like a ball thrown in the
air comes to the top of its arc, slows, stops, and starts
to fall. The crash of the long fall may be the Big Bang to
the beginning of another universe, as the fireball formed
at the end of the contraction leaps outward in another
great expansion.6 Such a universe is said to be closed, and
If the universe has achieved escape velocity, it will
continue to expand forever. The stars will redden and die,
the universe will be like a limitless empty haze, expanding
infinitely into the darkness. This space will become even
emptier, as the fundamental particles of matter age, and
decay through time. As the years stretch on into infinity,
nothing will remain. A few primitive atoms such as
positrons and electrons will be orbiting each other at
distances of hundreds of astronomical units.7 These
particles will spiral slowly toward each other until
touching, and they will vanish in the last flash of light.
After all, the Big Bang model is only an assumption. No one
knows for sure that exactly how the universe began and how
it will end. However, the Big Bang model is the most
logical and reasonable theory to explain the universe in
modern science. 
1. Mache, Dinah L. Astronomy. New York: John Wiley & Sons,
Inc., 1987. p. 128.
2. Ibid., p. 130.
3. Silk, Joseph. The Big Bang. New York: W.H. Freeman and
Company, 1989. p. 60.
4. Holt, Terry. The Universe Next Door. New York: Charles
Scribner's Sons, 1985. p. 326.
5. Ibid., p. 327.
6. Caes, Charles J. Cosmology: The Search For The Order Of
The Universe. USA: Tab Books Inc., 1986. p. 72.
7. Gribbin, John. In Search Of The Big Bang. New York:
Bantam Books, 1986. p. 273.
Boslough, John. Stephen Hawking's Universe. New York:
Cambridge University Press, 1980.
Caes, J. Charles. Cosmology, The Search For The Order Of
The Universe. USA: Tab Books Inc., 1986.
Gribbin, John. In Search Of The Big Bang. New York: Bantam
Books, 1986.
Holt, Terry. The Universe Next Door. New York: Charles
Scribner's Sons, 1985.
Kaufmann, J. William III. Astronomy: The Structure Of The
Universe. New York: Macmillan Publishing Co., Inc., 1977.
Mache, L. Dinah. Astronomy. New York: John Wiley & Sons,
Inc., 1987.
Silk, Joseph. The Big Bang. New York: W.H. Freeman and
Company, 1989.


Quotes: Search by Author