space the final frontier

"BIG BANG THEORY" is one of the largely accepted probability for the birth of our universe. But what would have been the situation before the big bang took place ? what substance/what matter was there which eventually caused "big bang" ? If there was anything then how long it was there ?

No they don't, and the question was about before the big bang not the steps of the big bang anyway.

The very early universe, which is still poorly understood, was the split second in which the universe was so hot that particles had energies higher than those currently accessible in particle accelerators on Earth. Therefore, while the basic features of this epoch have been worked out in the big bang theory, the details are largely based on educated guesses.

All our understanding of the very early universe (cosmogony) is speculative. No accelerator experiments currently probe sufficiently high energies to provide insight into this period. Scenarios differ radically. Some ideas include the Hartle-Hawking initial state, string landscape, brane inflation, string gas cosmology, and the ekpyrotic universe. Some of these ideas are mutually compatible, others are not.

If supersymmetry is correct, then at this time the four fundamental forces - electromagnetism, weak nuclear force, strong nuclear force and gravity - all have the same strength, so they are possibly unified into one fundamental force. Little is known about this epoch

The temperature, and therefore the time, at which cosmic inflation occurs is not known for certain.

No known physics can explain the fact that there are so many more baryons in the universe than antibaryons. In order for this to be explained, the Sakharov conditions must be met at some time after inflation. There are hints that this is possible in known physics and from studying grand unified theories, but the full picture is not known.

Brandon, one can study the universe their whole life but their guesses are still going to be limited by the physical evidence. I am only interested in "nearly absolute" truths and so for the most part I am not interested in other peoples wacky unsubstantiated theories. Some key excerpts from this Wiki page you have provided are...

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The very early universe, which is still poorly understood, was the split second in which the universe was so hot that particles had energies higher than those currently accessible in particle accelerators on Earth. Therefore, while the basic features of this epoch have been worked out in the big bang theory, the details are largely based on educated guesses.

Quote:

All our understanding of the very early universe (cosmogony) is speculative. No accelerator experiments currently probe sufficiently high energies to provide insight into this period. Scenarios differ radically. Some ideas include the Hartle-Hawking initial state, string landscape, brane inflation, string gas cosmology, and the ekpyrotic universe. Some of these ideas are mutually compatible, others are not.

Quote:

If supersymmetry is correct, then at this time the four fundamental forces - electromagnetism, weak nuclear force, strong nuclear force and gravity - all have the same strength, so they are possibly unified into one fundamental force. Little is known about this epoch

Quote:

The temperature, and therefore the time, at which cosmic inflation occurs is not known for certain.

Quote:

No known physics can explain the fact that there are so many more baryons in the universe than antibaryons. In order for this to be explained, the Sakharov conditions must be met at some time after inflation. There are hints that this is possible in known physics and from studying grand unified theories, but the full picture is not known.

....Inflation is a concrete mechanism for realizing the cosmological principle which is the basis of our model of physical cosmology: it accounts for the homogeneity, isotropy of the observable universe. In addition, it accounts for the observed flatness and absence of magnetic monopoles. Since Guth's early work, each of these observations has received further confirmation, most impressively by the detailed observations of the cosmic microwave background made by the Wilkinson Microwave Anisotropy Probe (WMAP) satellite. This analysis shows that the universe is flat to an accuracy of at least a few percent, and that it is homogeneous and isotropic to a part in 10,000.

In addition, inflation predicts that the structures visible in the universe today formed through the gravitational collapse of perturbations which were formed as quantum mechanical fluctuations in the inflationary epoch. The detailed form of the spectrum of perturbations called a nearly-scale-invariant Gaussian random field (or Harrison-Zel'dovich spectrum) is very specific and has only two free parameters, the amplitude of the spectrum and the spectral index which measures the slight deviation from scale invariance predicted by inflation (perfect scale invariance corresponds to the idealized de Sitter universe). Inflation predicts that the observed perturbations should be in thermal equilibrium with each other (these are called adiabatic or isentropic perturbations). This structure for the perturbations has been confirmed by the WMAP satellite and other cosmic microwave background experiments,[35] and galaxy surveys, especially the ongoing Sloan Digital Sky Survey. These experiments have shown that the one part in 10,000 inhomogeneities observed have exactly the form predicted by theory....