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The Question
(Submitted June 29, 2006)
I have trouble seeing how time came to existence from the Big Bang.
If this is the case, it will mean no time will before the Big
Bang they would be no time for something to cause the Singularity
to explode it will be frozen in time without causing any Big Bang.
The Answer
Thanks for your excellent question. You are among some of our great
scientific thinkers when it comes to wondering about the beginning of
time. The truth is that, we don't yet have a definitive answer. The Big
Bang certainly suggests that time began at the first instant of the Big
Bang, since before then, the universe was collapsed into a
singularity. The notion of time within the Big Bang scenario is discussed
at length by Stephen Hawking. Everything is squeezed down to zero and such
physical quantities as spacetime become infinite. The singularity is the
point at which time has no meaning.
However, there are other theories about our universe that suggest that there
was indeed a time before the initial "bang." Two of the most popular
theories are pre-Big Bang theory (using string theory) and the Ekpyrotic
scenario (using the collision of "D-branes"). In these theories,
the pre-big bang universe was very sparse and weakly interacting, but did
eventually give rise to a sudden transition that is similar to our "big
bang." We recommend an excellent article on the subject at :
http://www.sciam.com/article.cfm?articleID=00042F0D-1A0E-1085-94F483414B7F0000
Hope this helps,
Georgia & Mike
For "Ask an Astrophysicist"
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