The Origin of the Earth

The Early History of the Universe

 

The history of the Universe may be described in the following stages:

• At the beginning of the Universe (ca. 13 billion years ago) all matter was in one place at a single instant. This event in cosmological parlance is known as a 'singularity', a term which describes the inference that an infinitely large amount of matter is gathered at a single point in space-time.
• At the Big Bang there was a huge expansion of matter, an expansion which has continued ever since.
• However, between 10-50 and 10-30 sec after the big bang there was a particularly rapid expansion of the Universe. This process is known as inflation. Later expansion slowed to a more normal rate.
• During inflation the part of the Universe that we see today expanded by a factor of 1060. At this point the universe was permeated with radiation and subatomic particles (plasma/dark matter).
• After 100 000 yrs conditions in the Universe were similar to those today inside the sun. An almost uniform plasma of electrons and hydrogen and helium ions filled the Universe. At this time the free electrons acted as a block to photons — generated from the light energy generated in the Big Bang, and prevented them escaping and rendering the early Universe opaque.
• Aafter 300 000 yrs temperature dropped to 4500°K gave rise to atomic matter (hydrogen helium and deuterium) and because the electrons were now removed (in the atoms), radiation streamed out and the Universe became transparent.
• As the universe continues to expand the radiation will appear to be derived from a much cooler body, so that today the Cosmic Background radiation is 3.73 deg above absolute zero.