The Big Bang

Introduction
The history of the Big Bang begins with observations of astronomers around 1911 of galaxies moving away from us. This discovery was made by the study of spectra of stars and galaxies. Each of these bodies that emit electromagnetic radiation has spectra that can be observed when their light is spread to the component wavelengths. White light for example would have all the wavelengths of visible light- from read to violet. Stars, galaxies and other heavenly bodies other hand may have spectra that also includes invisible electromagnetic wavelengths e.g. x-ray and gamma rays. All the same, as space expands galaxies move away from us and wavelengths of their light increases producing a so-called red shift in their electromagnetic spectrum. The opposite of this is a blue shift that would be produced if the galaxies were moving towards us. These occur by the Doppler Effect taught in high school. Doppler Effect is apparent wavelength of source appears to change when there is relative motion between the source and receiver.

It was also observed that galaxies further from the Milky Way move away faster from us than galaxies closer to us. In 1920, Edwin Hubble discovered that the velocity (V) at which a galaxy moves away from our galaxy can be related to their distance from us (D) by V=HD where H is Hubble's constant 65 kilometers per second per megapersec. One Megapersec is 3×1019km. A galaxy that is 1 megapersec away is moving at 65 kilometers per second from us. One that is two megapersecs away is moving at 130km/s and so forth. This gives an impression that our galaxy is at the centre of the universe. However it has been shown that galaxies move away from each other in a similar manner. The universe is expanding.








Fig1.3 Picture of galaxies receding from the Milky Way
With this in mind astronomers hypothesized that at one point in history the universe was such that all the matter, space and time was packed at a small point, called a singularity. The point stared to expand, explosively. The Big Bang!

According to the Big Bang theory, a ball (the size of a proton) of infinite density and coming out of nothing for an unknown reason starts to expand and cool to the present working order that supports life. These extreme conditions led the English astronomer Sir Alfred Hoyle (a big antiBBT) to name it ridiculously, the Big Bang Theory. Unfortunately for him, this theory has become astronomers favorite and, because of its name, very popular. Nowadays you can here it on the lips of junior high school kids or theologians. He however went ahead among other astronomers Herman Bondi and Thomas Gold to propose another different theory in 1948- the Steady State theory- of a universe that has always existed. In their new theory, matter forms from nothing at the rate of a few atoms per cubic mile per year. Their theory had its good moments when it was hailed for explaining formation of elements. According to it new elements are formed when stars explode and spread their atoms which later fuse creating heavier elements-Neuclosynthesis. However it failed to explain to the origin of the large amount of Helium in the universe that makes about 27% of all the matter that exists. Besides it needed an alternative explanation for the Cosmic Microwave Background Radiation (CMB) - page----. Its 2 weaknesses are however the basics by which the BBT is founded. Sir Alfred died in 2001. He never believed the universe ever begun.

The BBT is the most successful creation theory after the Biblical narration and is almost as unanimously accepted as the Darwinian theory of evolution. Hence it must come as a relief to Christians that the BBT supports a universe that started at a time finite in the past. If it didn't it would reduce the chances of a creator to zero percent probability as is the case of the Steady State Theory.