The Birth of the Big Bang and the Timeline of Everything We Know

Modern scientific thought owes itself to the contributions of many great men and women. Without these individuals, our universe would (literally) look quite different. However, there are two scientists in the field of cosmology who stand out among all the rest: Edwin Hubble and Georges Lemaître. By 1930, other cosmologists had concluded that the static (non-evolving) model of the universe was unsatisfactory.

This discovery is largely due to the efforts of Edwin Hubble. Using the world’s largest telescope, which is located at Mt. Wilson in California, he showed that the distant galaxies all appeared to be receding from us. What"s more, these far flung galaxies were traveling away from us at speeds proportional to their distances -- Enter Lemaître -- Lemaître used these findings to draw attention to his earlier paper, in which he explained the relationship between the distance of a galaxy and the recession velocity of that same galaxy. By putting together Hubble’s observations with Lemaître’s paper, a majority of astronomers became convinced that the universe was indeed expanding. This revolutionized the study of cosmology.

Why was this find so notable? Shortly after this discovery, Lemaître reasoned that traveling back in time should lead to an epoch in which all the matter in the universe was packed together in an extremely dense state – a primeval atom. And this was the birth of Big Bang cosmology.

So, let us take a moment to delve into the Big Bang--into the timeline of everything that has ever existed...

Image:
NASA/ESO