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Aardvark Communications:

A Practical Guide to Astronomy


The Big Bang: When Time Began


Stephen Hawking

At the age of 21, Stephen Hawking discovered he had ALS (Lou Gerhrig's disease.) He would gradually loose the use of his muscles, except for his heart, his liver and his brain. Despite his disability, he had decided to focus his efforts on cosmology, the study of very large things, like our universe, black holes and the beginning of time. In 1979 he was awarded the same chair, Professor of Mathematics, as Sir Isaac Newton.

The Theory

Stephen Hawking calculated that black holes emit quantum radiation. Based on Einstein's theory of bending light, Hawking was able to figure when enough mass is concentrated as in a large collapsing star, that curvature becomes extreme enough to prevent light from escaping- thus you have a large black hole.

A black hole has a point of infinite density and zero size, called a "singularity". Hawking then theorized; by reversing time, using the black hole model, time must have had a beginning, a point in the past where time as we know it began; 10 to the -43 second. This is the point in time where we can not go any further back- the outer limit.

A History of the Universe in 4 Frames

At the beginning of time, from complete nothingness, a cosmic explosion ignites.
The thurst from the explosion sends billions of tons of energy through space and the elements begin to cool.
Galaxies begin to take shape while still moving away from the initial point of ignition
The universe continues to expand to this very day.

And Then What?

There are two schools of thought regarding what will happen to our universe. Some scientists believe that the universe will continue to expand forever. Other scientists believe the universe may slow its expansion, reach a peak expansion distance, then begin to contract under the pressure of gravity, until we reach a "Big Crunch."

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