Event 1

13.798 billion years ago


Timeline of the Universe
Timeline of the expanding universe from 13.7 billion years ago to the present.
Credit: Image courtesy of NASA.

Some 13.798 billion years ago, our universe (matter, energy, space, and time) came into existence. Exactly how and why this happened is not really understood. It is believed that all of the matter that now exists in the universe was originally compressed into a point smaller than the size an atom called a singularity, which rapidly expanded. This expansion, first faster than the speed of light, has been dubbed “The Big Bang.” The matter of the universe first consisted of a superhot plasma from which the first subatomic particles formed. As the universe expanded, in its first few minutes, it began to cool, forming the first primeval atoms: hydrogen, helium, and lithium.

Less than one-thousandth of a second after the Big Bang, two types of particles formed: matter (which our universe is composed of) and antimatter. These particles, called “quarks” (the matter) and “antiquarks” (the antimatter), met and annihilated each other. It is believed that there was a slight asymmetry or imbalance in the number of each type of particle, with matter very slightly outnumbering antimatter by about one particle per billion. Our resultant universe is composed of that slight surplus of matter versus antimatter. These quarks, in groups of three, formed protons and neutrons, the major components of atoms.

13.7 billion years of temperature flluctuations on earth
Early universe temperature fluctuations are illustrated in this image of the 13.7 billion year-old cosmic microwave background radiation temperature fluctuations detectable across the full sky with a radio telescope.
Credit: Image courtesy of NASA/WMAP Science Team.


The “afterglow” of the Big Bang event has been measured in the form of the cosmic microwave background radiation, which records the basic temperatures that permeated the very early universe, averaging about 2.7 Kelvin (Celsius) above absolute zero as seen today (it would have looked a lot hotter back then, about 3000 degrees, before the expansion of the universe) . About one % of the static on your television (when not on a station) comes from this ancient cosmic radiation from about 13.4 billion years ago.






Experimental subatomic particle colliders attempt to recreate the high-energy, high temperature conditions that existed in the universe a split-second after the “Big Bang”. This allows us to look at the subatomic world of particle physics, and to examine the primordial particles and forces that make up matter and energy. On another scale, astronomical studies of distant galaxies show that they are all retreating from each other at an ever-accelerating rate, pointing back to a single origin (the singularity) of the entire universe. Observations of a certain class of exploding stars have allowed us to calibrate the rate of expansion, suggesting an age of 13.798 billion years for the Big Bang.

We do not know, however, what forces are driving and accelerating this universe expansion. Mysterious terms such as “dark matter” and “dark energy” have been used to denote these unknown and as yet undetected forms of matter and energy.


Universe's first fireworks
The Universe’s first fireworks. An image of the area of the universe containing the Ursa Major constellation taken with NASA’s Spitzer Space Telescope, but with light from stars, galaxies and other sources removed. The background light remaining (brighter objects seen in white and yellow, dimmer objects in darker colors) is from a universe that is still very young, less than a billion years old, when it contained very early objects such as huge stars or black holes.
Credit: Image courtesy of NASA/JPL-Caltech/GSFC


We are talking about the origins of all matter‚ every atom of your body, every atom of the air we breathe, the food we eat, the water we drink, not to mention every atom of the earth, the solar system, the galaxy, and the universe. Exactly how and why this happened is one of the great mysteries of science and metaphysics.

Interestingly, the term “Big Bang” was first coined in 1949 by astronomer Fred Hoyle who did not believe in the concept, and used the term to ridicule the theory. Hoyle believed the universe existed in a “steady state” form, with no beginning or end. As time went on, more and more studies supported a definite, singular origin for the universe from which all matter expanded, and the term “Big Bang” stuck.






The beginning of the universe, for beginners – Tom Whyntie:


NASA web pages on Big Bang Theory:


Age of the Universe:

NASA WMAP website, investigating early phases of the evolution of the universe:

PBS website timeline:

Short summary from CERN (European Organization for Nuclear Research):

NSF (the U.S. National Science Foundation) page on the origins of the universe:

A short video about the origins of the universe and its relation to the Big Bang, very informative and in plain language.



Coles, Peter. Cosmology: A Very Short Introduction. Oxford: Oxford University Press. 2001.

Krauss, Lawrence M. A Universe From Nothing: Why There Is Something Rather Than Nothing. New York: Free Press (A Division of Simon & Schuster, Inc.) 2012.

Mather, John C. and John Boslough. The Very First Light: The True Inside Story of the Scientific Journey Back to the Dawn of the Universe. New York: Basic Books. 2008.

May, Brian, Patrick Moore, and Chris Lintott. BANG! The Complete History of the Universe. Baltimore: Johns Hopkins University Press. 2008.

Murdin, Paul. Secrets of the Universe: How We Discovered the Cosmos. Chicago: University of Chicago Press. 2009.

Panek, Richard. The 4 Percent Universe: Dark Matter, Dark Energy, and the Race to Discover the Rest of Reality. Boston/ New York: Houghton Mifflin Harcourt. 2011.

Ronan, Colin A. Universe: The Cosmos Explained. London: Quantum Publishing. 2007.

Seife, Charles. Alpha and Omega: The Search for the Beginning and the End of the Universe. New York: Penguin Books. 2003.

Silk, Joseph. The Big Bang: Third Edition. New York: Henry Holt and Company, LLC. 2001.



Cosmic Voyage. Narrated by Morgan Freeman. IMAX and Warner Brothers. 2002.

Origins: Fourteen Billion Years of Cosmic Evolution. NOVA, WGBH, Boston Video. 2004. Hosted by Neil deGrasse Tyson.

The Universe. The History Channel. (A multi-year television series).
Understanding the Universe: Introduction to Astronomy. The Teaching Company. 2007. (96 presentations by Alex Filippenko).

Universe: A Journey from Earth to the Edge of the Cosmos. Quercus. 2008.


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