9 December 2003
The Beginning and Ending of the Universe
The following essay is about the beginning and ending of the universe. The sources I will be using are a "The Creation of the Universe" a film by Timothy Ferris, and the forth edition Astronomy book by Chaisson and Mcmillan.
There are many theories of how the universe all began and how it will end. I will be emphasizing on the creation and evolution of the universe. I will be referring to the theory most widely used: The Big Bang theory. This theory basically states that everything in the universe was at a single point, that point exploded, sending parts and debris everywhere at very high speeds, which evolved into the universe. This all happened somewhere between 9 and 14 billion years ago. The age of a critical-density universe with no cosmological constant is about 9 billion years old.
The universe was composed entirely of radiation when it all began. Radiation ultimately produced everything we see around us. The earliest known time that can be described by modern physics is called Planck's time. This time is 10-43 seconds. We do not know what happened before Planck's time because we lack a theory. We need a quantum theory of gravity.
GUT's are the Grand Unified Theories, which are theories that express the actions of the single force that results from combining of the strong, weak, and electromagnetic forces. In the beginning there was 1 force, supergravity. There are now 4 forces in nature.
10-34 seconds after the Big Bang the temperature was 1028 kelvins. For a moment the universe entered a very strange, and unsteady high-energy state. Temporarily empty space gained massive pressure, which momentarily overpowered the pull of gravity. This caused the universe to expand very...