Happy Little Accidents: the bang that started it all

We’re all familiar with the Big Bang theory: you know, the one that literally explains how the entire universe originated and where it is headed. Essentially, almost 14 million years ago, an extremely hot, dense, and subatomic point unconventionally exploded and caused a rapid expansion of space itself. Since then, the cosmos has continued to stretch and cool. In the process, a flood of matter and radiation was released that would go on to form our stars and galaxies, along with everything we know to exist. It’s important to note that the definition of a scientific theory may vary slightly from common usage of the word. A scientific theory is an explanation of natural phenomena based on tested hypotheses. It is fact based on evidence and supported by the scientific community, not merely a guess or speculation. 

The story of the Big Bang theory begins with Albert Einstein in 1915 when he developed the general theory of relativity. Einstein’s equations, which describe the structure of space and time, suggested that the universe should not be static but rather expanding. However, this directly contradicted the accepted beliefs of scientists at the time; therefore, Einstein did not fully pursue his findings (it wasn’t until later that Einstein admitted this to be “the greater blunder of [his] life”). 

In 1929, the American astronomer Edwin Hubble showed that the distant galaxies all appeared to be receding from us at speeds proportional to their distances; Hubble’s Law stated that the farther galaxies recede faster. He first made such observations when using the world’s largest telescope at Mount Wilson in California to analyze the redshift of nebulas, not realizing what he would stumble upon. 

Soon after, in 1931, the idea of an expanding universe appeared in a paper by George Lemaitre, a Belgian cosmologist and Catholic priest. From here, Lemaitre did much of the heavy lifting by appealing to the new quantum theory of matter. He arrived at the conclusion that at some finite point the universe was an incredibly small single particle which he called the “primeval atom.” The problem with classic general relativity is that rewinding the universe results in infinite temperature, density, and curvature which quite literally would break the laws of physics. However, the primeval atom could indeed be classified as finite if it were compressed into a single quantum state. Perhaps one of the most interesting things about Lemaitre is his resolution to keeping religion and science entirely separate by treating them as different, parallel interpretations of the world, both of which he believed in.  

However, many skeptics remained, especially the English astronomer Sir Fred Hoyle. In 1946, Hoyle, along with Thomas Gold and Hermann Bondi, watched Rober Hamer’s horror film Dead of Night. In the movie, a young architect is about to die in a dream. He wakes up and the story restarts exactly as it began. Hoyle and his colleagues were intrigued by the idea that things could change and yet stay the same for an eternity, leading them to propose the idea of the steady-state universe, which still expands but new matter fills in the gaps so it lasts forever. The steady-state model, although wrong, became quite popular in the ’50s. While talking about it on a BBC radio show, Hoyle mockingly coined the alternative the “Big Bang,” not believing that all matter was created in one explosion rather than overtime. Given the historical circumstances, it wouldn’t be very difficult to figure out why many people were predisposed against anything resembling a large bomb-like explosion.

Nevertheless, the idea of the Big Bang continued to evolve thanks to the life work of many great scientists, including Soviet-American physicist and cosmologist George Gamow. However, the real smoking gun was in 1964 when Americans Robert Wilson and Arno Penzias, an astronomer and physicist, respectively, attempted to detect astronomical radio waves in the halo around the Milky Way. They unexpectedly began to hear a hissing sound which they attributed to either radio waves from New York, equipment malfunctions, or, believe it or not, pigeon poop as two pigeons had taken to living inside the antenna. Nevertheless, even after trapping the birds and conducting a thorough cleaning, the hissing noise continued in all directions, leading the scientists to continue experimenting. Eventually, they concluded that they had detected cosmic background radiation, the leftover heat or “afterglow,” representing the universe’s earliest light and an echo of the Big Bang. Fun fact, the metal trap built to capture the pigeons remains on display for visitors to the Smithsonian Air and Space Museum.

In 1978, Wilson and Penzias received the Nobel Prize in Physics to the vexation of many others who believed that they deserved credit for the role they had played in the buildup to the discovery. 

While it’s clear that the overall development of the Big Bang theory was no accident, but rather a series of dedicated and brilliant scientists actively seeking groundbreaking discoveries, it is incredible to observe how many of these individual parts of a whole were often stumbled upon or inspired by the most mundane of things. When it comes to something as novel as the Big Bang theory, it makes perfect sense that things not even fathomable before their existence come about in the most unexpected ways.