BIRTH OF A GIANT

Every birth is recorded and that must be true for death as well. The birth and death of stars are imprinted in the fabric of the cosmos. For modern humans, digital records serve the purpose.Fossils bear the indisputable evidence of the foregone era of plants and animals. How about the Universe? In fact, the evidence of the ‘oldest birth’ is everywhere. The exploration and eventual mapping of that proof turned Cosmology from a purely theoretical science to most exciting scientific quest of our generation.

The standard Cosmology theory suggests that the Universe began its birth with a bang –Big Bang-so we call it .This is a misnomer as there was not any bang in the first place .As we know, the bang (sound) needs to have a vibrating particle to generate it and then it requires a medium for the vibration to propagate. Since 'Big Bang' is the beginning of anything we can imagine, it is logical to assume that this moment of creation was in perfect silence. The creation of space and time were followed by matter and energy and that led to the manifestation of every thing we know today, including the life.

The Big Bang Theory was one of the contenders for the origin of the Universe, among many such theories existed during the 1930’s. The other prominent theory was the ‘Steady State Universe’ advocated by Fred Hoyle, a British scientist. Georges Lemaitre ,a Belgian Catholic priest, Astronomer and Physics professor, applying Einstein’s Theory of Relativity, proposed the ‘Big Bang’ as the possible origin of the Universe. Initially, it was known as ‘Hypothesis of the Primeval Atom’ as Lemaitre called it, though it would be known as Big Bang’ theory later. This theory essentially suggested that the Universe is expanding and in the past Universe must have been small, smaller than an atom where all the forces co-existed. The ‘explosion of this cosmic egg’ created the Universe which has been expanding since its birth and continues even today, 13.7 billion years after the cosmic origin.

Though Lemaitre derived his conclusion based on ‘Theory of Relativity’, the father of relativity was skeptical about this finding. Einstein reportedly remarked "Your math is correct, but your Physics is abominable”. However, he appreciated Lemaitre’s argument that a static-Einstein model of the universe could not be sustained indefinitely into the past. Few years before this, Alexander Friedman had reached a similar conclusion but he died in 1925.As a Physicist, living and working in USSR did not offer him much attention among his peers in those days.

In 1929, American Astronomer Edwin Hubble made a startling discovery based on the observation of galaxies spanning few yeas. Hubble along with an assistant worked at the Mount Wilson observatory in California, using the world’s larges telescope of those days. Ignoring the cold nights of California Mountains, Hubble spent a few years in photographing different galaxies and discovered the relation between the redshift and distance of the galaxies. Milky Way was considered to be the only galaxy in the Universes but Hubble’s observations revealed that the Universe contains many such galaxies. Hubble reported that aside from a few neighboring galaxies all the galaxies are receding from each other into the galactic wilderness .Although the significance of redshift was known before Hubble’s findings, he was credited with establishing a relation that indirectly measured the galaxy distances.
The red shift is the Doppler Effect of light in which an object moving away from an observer emits a wavelength that will shift toward a lower frequency or higher wavelength which is red. As a source sound passes an observer, depending the speed of the source, the observer perceives a lower frequency or pitch. The apparent change in frequency is known as the Doppler Effect, which is employed in Doppler radar, and its counter part for the light is referred as Redshift.

Hubble’s discovery provided a major support to the Big Bang theory of Lemaitre, who argued that if we go back in time from the current expansion of the Universe, there must exist a state of the Universe with infinite density and temperature referred to as singularity. This dense and hot phase of the Universe existed 13.7 billion years ago gave way to the birth of the expanding Universe, in a process called Big Bang. This idea was radical in nature as it contradicted the widely supported ‘Steady State Theory’ of Fred Hoyle, which claimed that though the expanding Universe creates new matter, and it has no beginning and no end.Hoyle never accepted Lemaitre’s theory of finite beginning, and the term ‘Big Bang”was Hoyle’s sarcastic remark about that in one of his BBC radio broadcast in 1949.Although Hoyle coined the term ‘Big Bang’ , in an apparent rejection of that idea, the name stuck and Limiter's theory is now known as Big Bang Theory. After the second world war, the support for these theories were split , eventually the steady state theory of Hoyle faded from the scientific community like the receding galaxies.However,Hoyle remained resistant to the Big Bang theory until his death in 1984.
The discovery of CMB in 1964, secured the position of the Big Bang as the most acceptable Cosmological theory.