The Idea That the Big Bang Destroyed
What happened before the Big Bang? From a cosmic perspective, it's impossible to know for sure (for now, at least). But there is a similar question we can answer! What was there before the Big Bang theory?
For half a century, The Big Bang model of the Universe has stood out as the dominant theory for how everything came to be. But before coming to prominence, the Big Bang struggled to take hold in the minds of cosmologists. Instead, many preferred Steady State theory. Championed by English astronomer Sir Fred Hoyle, the theory states that the observable Universe remains essentially the same at all locations of time and space. Stars and planets form, die, and form again, but the density of matter does not change. This means that the Universe had no beginning. It also means it will have no end. The Universe simply is.
During Steady State's heyday in the 1940s and 50s, Hoyle and his contemporaries defended the theory with intellectual vigor, winning over a significant portion of the scientific community. To reconcile their idea with Edwin Hubble's observations that the Universe was expanding, they suggested that matter was created in between distant galaxies. As long as a single atom of hydrogen per cubic meter were squeezed out of the stretching fabric of space every ten billion years, their theory would check out with observational data.
"If matter were spontaneously created at this meager rate, then each and every location in the Universe -- on average -- would always contain the same number of galaxies, the same population of stars, and the same abundance of elements," astrophysicist Ethan Siegel described in his recent book Beyond the Galaxy.
Compared to the notion of a fiery, primeval creation event from which the entire Universe sprouted -- what Hoyle snarkingly dubbed the "Big Bang" -- this was not that far-fetched. Hoyle derided the Big Bang model as an "irrational process" that "can't be described in scientific terms," akin to creationism.
But in 1965, Steady State Theory lost a decisive scientific battle. Radio astronomers Arno Penzias and Robert Woodrow Wilson realized that the faint, blanketing noise emanating from their antenna's receiver at Bell Labs originated from the universe itself. It was the afterglow of the Big Bang, the cosmic microwave background radiation! Hoyle and his fellow Steady State proponents scrambled to account for the new observations.
"Perhaps this was not radiation left over from the Big Bang, but rather was very old starlight, emitted from stars and galaxies strewn across the Universe," Siegel described. This light could have been scattered and re-emitted by the atoms constantly popping into existence.
Alas, further observations discounted this explanation, and the Big Bang model swiftly ascended to take its place as the leading theory accounting for the Universe.
Like the slow, creeping heat death of the universe predicted by the Big Bang model, in which the Universe expands forever until what's left is too devoid of energy to sustain life, the Steady State theory gradually fizzled out in scientific circles. Hoyle, however, defended his theory until his dying day in 2001, never accepting the overwhelming evidence for the Big Bang.