Big Bang

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The '''Big Bang''' is the widely accepted (by scientists) theory of how the [[universe]] began. According to the theory, all of space and time (spacetime) "began" about 13.7 billion (± 200 million) years ago<ref> [http://www.astro.ucla.edu/~wright/age.html The age of the Universe can also be estimated from a cosmological model based on the Hubble constant and the densities of matter and dark energy. This model-based age is currently 13.7 +/- 0.2 Gyr. But this Web page will only deal with actual age measurements, not estimates from cosmological models. The actual age measurements are consistent with the model-based age which increases our confidence in the Big Bang model.]</ref>
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The '''Big Bang''' is the widely accepted (by scientists) theory of how the [[universe]] began. According to the theory, all of space and time (spacetime) "began" about 13.7 billion (± 200 million) years ago, and has been [[Expanding universe|expanding]] ever since.<ref> [http://www.astro.ucla.edu/~wright/age.html The age of the Universe can also be estimated from a cosmological model based on the Hubble constant and the densities of matter and dark energy. This model-based age is currently 13.7 +/- 0.2 Gyr. But this Web page will only deal with actual age measurements, not estimates from cosmological models. The actual age measurements are consistent with the model-based age which increases our confidence in the Big Bang model.]</ref>
 
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==See Also==
 
==See Also==
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*[[Expanding universe]]
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*[[Red shift]]
 
*[[Fun:Big_bang_theory|Another theory]]
 
*[[Fun:Big_bang_theory|Another theory]]
  

Revision as of 01:21, 1 February 2009

— Outline Only —
This article is only a brief description of the subject, and is not intended to give a full explanation.
Check out the "see also" or "references" sections, or Wikipedia's article for more detail.

The Big Bang is the widely accepted (by scientists) theory of how the universe began. According to the theory, all of space and time (spacetime) "began" about 13.7 billion (± 200 million) years ago, and has been expanding ever since.[1] .

Contents

Question

"What was there before the Big Bang?" the only possible answer is:
"The question is nonsensical, there was no time (or space) for anything to exist in, so the word before is meaningless."

As this is non-intuitive and goes counter to all everyday human experience it is the major point upon which popular understanding fails.

Salvation, for one editor at least, came with the Planck Time. The Planck Time is the shortest meaningful length of time. It is somewhere around 10-43 seconds, which is extremely short, but not zero. It is not possible to know what happened less than one Planck Time after the Big Bang. Indeed, it is not just not possible to know what happened, it is actually meaningless to even ask the question. That being the case the question of what happened before the Big Bang is also meaningless. We just have to lump it and get on with asking questions which are meaningful.

Hawking's book A Brief History of Time gives a reasoned explanation of the Big Bang and subsequent events but is popularly reckoned to be intensely dense to the point of unreadability. Another book A Briefer History of Time has since been published.[2]

Since the start of the universe at time zero and, presumably, volume zero there has been an expansion of space to its present size. This was first intimated by Edwin Hubble, who determined that the many galaxies he observed were moving away from each other. It was by extrapolating back with Hubble's data that the initial compression of the universe was proposed.

Theory

The Big Bang is a theory and is undergoing constant amendment and recalculation - this is the correct scientific method and does not imply doubt or any specific uncertainty. It is without doubt that The Big Bang Theory is not going to be proved in the near future or possibly ever.

TOE (Theory of Everything)?

It is notable that the disciplines of Quantum Physics, Relativity and Astrophysics all converge in the Big Bang Theory - a first for science.

Addendum: God?

Theists of all stripes have attempted to use the theory as a "proof" of the existence of God:

"How was the Big Bang initiated, if not by a supernatural being?" they ask.
To which there is only one reply necessary:
"How was the supernatural being created if not by a supernatural being?"
And so on ad infinitum.

This paradox is unsolvable, so in the end, it comes down to a question of faith, or lack thereof.

In A Brief History of Time, Stephen Hawking outlines the mathematical use of imaginary time which results in the descripton of the universe as being of a hyperspherical nature without start or end - these being merely points on a "surface" undistinguished from others. The upshot is that the requirement for "start" and "cause" are removed, as is the need for faith (a concept which has no place in science).

Interestingly enough, the Big Bang theory was first proposed by Catholic priest and professor of physics Georges Lemaître. He first brought the theory to public attention after the discovery of redshift by nearby nebulae, although it was Fred Hoyle who coined the actual name as a derisory term. Compared with current Big Bang theory, which incorporates aspects such as Inflation, LeMaitre hypothesized that all matter for the universe came forth from a "primeval atom", today more commonly described as a singularity.

See Also

Footnotes

  1. The age of the Universe can also be estimated from a cosmological model based on the Hubble constant and the densities of matter and dark energy. This model-based age is currently 13.7 +/- 0.2 Gyr. But this Web page will only deal with actual age measurements, not estimates from cosmological models. The actual age measurements are consistent with the model-based age which increases our confidence in the Big Bang model.
  2. A Brief History of Time, ISBN: 0-553-34614-8
    A Briefer History of Time, ISBN: 0-553-80436-7
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