GUTS and Inflation in the Big Bang
The Inflationary Period in the Theory of the Early Universe
Shortly after the initial big bang, the universe went through a period of very rapid expansion called the inflationary period.
Grand Unified Theories - GUTS
Einstein's general relativity theory is a theory of gravitation. Gravity is one of four fundamental forces in nature. The other three are electromagnetic forces, weak nuclear forces and strong nuclear forces. After completing this theory Einstein tried to come up with a unified field theory that combined the other fundamental forces of nature into a single theory. He did not succeed.
In recent years various theoretical workers have come up with theories that unify these fundamental forces. These theories are referred to as GUTs, which stands for Grand Unified Theories. Notice the plural. It is significant. There is more than one GUT theory because these theories are still in their infancy and we still have not yet had time to adequately test them to see which version is best. Eventually we will achieve better understanding.
Currently GUTs predict that at the very high temperatures and densities in the early stages of the big bang all four fundamental forces of nature were unified. The forces separated as the universe expanded and cooled. Gravity separated first, near the end of the Planck time.
At around 1E-36 to 1E-37 seconds (1E-36 refers to the power of 10 i.e. 1 times 10 to the minus 36th power.) after the big bang, the strong nuclear force separated, leaving the weak nuclear and electromagnetic forces still combined as the electroweak force. At this time the temperature of the universe had cooled to about 1E28 Kelvins, which was the beginning of the cooling off but hardly a cold snap.
Inflationary Period
This strong force separation caused a transition from a high cosmological constant (the cosmological constant is what Einstein put in his general relativity theory so that it would not predict the universe is expanding) to a zero cosmological constant. This transition in cosmological constants is similar to a phase transition and initiated a brief era of very rapid expansion just as water expands when it makes a transition from the liquid to the solid phase.
This stage of rapid expansion is called the inflationary era. During the inflationary period the universe grew to a size of about 10cm, a comfortable handful. This size seems small for the entire universe, but at the beginning of the inflationary era the universe was perhaps a billion times smaller than an atomic nucleus. The inflationary era ended when the universe was 1E-32 seconds old.
Perhaps as a respite from all this rapid inflation, things calmed down a bit. Not much happened until about 1E-12 seconds, when the weak and electromagnetic forces separated. Then the universe began to form matter.
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The Planck Time and the Big Bang
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Origin of Matter in the Universe
Further Reading
Greene, B., The Elegant Universe, Norton, 1999.
Barrow, J.H. and Silk, J., The Left Hand of Creation, Oxford, 1983.
Silk, J., The Big Bang, Times Books, 2000.
Harrison, E.R., Cosmology The Science Of the Universe, Cambridge, 1981.
Friedman, H., The Astronomer's Universe, Norton, 1998.
