In terms of theoretical physics, the Big Bang theory is one of the more concrete conceptions. Although we still don’t know what caused the Big Bang, proof of its occurrence is so compelling that it has progressed from a theory to an established fact. In the spirit of facts, here are eight fascinating facts about the creation of the universe that you may not be aware of.
1. The Big Bang Theory Was First Proposed by a Catholic Priest.
Unexpectedly, a Belgian Catholic priest was the first to describe the Big Bang theory. Well, a priest who was renowned for his mathematical and astronomical abilities. The concept was created in 1927 by Georges LeMaître while he was a student at MIT. LeMaître hypothesized that since galaxies were moving apart, they must once have been much closer together—possibly so close that under the pressure of that compression, they may have shrunk down to the size of a “primeval atom,” causing an explosion of unfathomable proportions.
LeMaître developed the Big Bang hypothesis, but someone else came up with the catchy moniker. That distinction belongs to Sir Fred Hoyle, an English astronomer who belonged to a group of academics who insisted that the cosmos was stationary rather than expanding or contracting. In 1949, when he was present to deny the event’s existence, he coined the phrase for the first time.
2. The Big Bang Could Have Occurred Around 26 Billion Years Ago.
If the existence of the Big Bang could be deduced from the increasing distance between galaxies, so could the time when it occurred. LeMaître and astronomer Edwin Hubble, the namesake of the Hubble Space Telescope, could calculate a galaxy’s velocity and speed using redshift—the shifting wavelength of cosmic light. Hubble estimated the universe to be only about 2 billion years old based on incorrect calculations [PDF].
Future generations of scientists corrected Hubble’s math errors, indicating that the universe was far older than previously thought, with the Big Bang occurring at least 13.8 billion years ago. Even that figure is not certain. The finding of “super-old” stars on the outskirts of the galaxy in 2023 prompted researchers from the University of Ottawa to hypothesize that the Big Bang could have occurred as long as 26.7 billion years ago. If you want you can also read – Astronomers Spot Mysterious Dark Spot on Neptune
3. Even Albert Einstein First Rejected the Big Bang Theory.
Despite being founded on solid facts, the Big Bang idea was widely rejected for decades until it became widely accepted. Albert Einstein was one of the skeptics, rejecting the idea when it was first proposed by LeMaître and later by a Soviet physicist named Alexander Friedmann. Einstein’s general theory of relativity was the greatest significant advancement since Isaac Newton, and while it explained many puzzling cosmic events, the Big Bang was not one of them.
This is because general relativity holds that the cosmos is intended to be motionless and unmoving. If galaxies aren’t drifting apart in the future, they can’t have been closer together in the past, rendering the Big Bang impossible. This explains Einstein’s unequivocal response to LeMaître: “Your calculations are correct, but your physics is abominable!” According to a paper discovered after his death, Einstein briefly addressed the hypothesis of a static universe even after the Big Bang became widely accepted.
4. You Can See the Big Bang With Your Own Eyes—on TV.
When experimental physicists Arno Penzias and Robert Wilson discovered direct evidence of the Big Bang in the form of radio waves spreading throughout the cosmos in 1965, the debate over whether the universe was moving or not came to an end. These waves, known as the Cosmic Microwave Background, are the cooled-off remnants of the Big Bang’s light.
You have, believe it or not, witnessed the Cosmic Microwave Background. And you’ve probably seen it more than once because the CMB generates the static signal (also known as “snow”) that you see on analog TVs and hear on radios when you change stations.
5. The Big Bang Most Likely Produced Temperatures in the Billions of Trillions of Degrees Celsius.
Contemporary study doubts that the universe was once constrained to the one atom mentioned by LeMaître. It has, however, been estimated that it spanned an area the size of a pinhead. Although it is practically evident that the Big Bang was the most powerful explosion in history, its exact magnitude is impossible to comprehend. The force unleashed at the Big Bang, according to Universe Magazine, was equivalent to 1054 megatons of TNT. To put that in context, hydrogen bombs, the most devastating weapons humans can devise, produce roughly 50 megatons of energy.
The Big Bang occurred quickly as well. Energy was hurled at the speed of light—300 million meters per second, a million times faster than hydrogen bombs. All of this incredible speed and power generated an equally incredible amount of heat. Temperatures might have soared to 1000 trillion degrees Celsius in a fraction of a second after the detonation, according to estimates.
6. The James Webb Space Telescope Nearly Proved the Big Bang Theory Wrong.
The largest challenge to the Big Bang theory in decades arose shortly after the James Webb Space Telescope was launched in 2021. It is the most powerful telescope in the world, allowing scientists to explore hitherto unobservable areas of the universe. It uncovered galaxies that were so huge and so old that our present knowledge of galactic formation and evolution failed to explain how they could have been produced so soon after the Big Bang.
The discovery posed two possibilities: either the Big Bang theory was erroneous, or the observations from the James Webb Space Telescope were incorrect. The second proved to be correct. NASA decided that the galaxies were far smaller in size than they first seemed, using more exact and reliable methods to calculate their distance—small enough for artificial intelligence to model their formation following the Big Bang.
7. The Big Bang Foretells the Demise of the Universe.
If turning back the clock on cosmic expansion takes us to the beginning of the universe, turning it forward could lead us to its conclusion. Several explanations for the universe’s demise have been presented, many of which are mirror reflections of the Big Bang.
The Big Freeze theory proposes that the universe will “die” when the distance between celestial objects becomes so enormous that energy becomes uniformly distributed and space reaches absolute zero temperature. Another theory is the Big Crunch, which postulates that the universe will one day stop expanding and begin compressing, eventually recreating the conditions for another Big Bang. A third scenario, known as Eternal Inflation, proposes that expansion is a never-ending process that only stops at some points in the universe, resulting in the formation of self-contained pocket universes such as the one we live in.
8. We Have No Idea What Happened Before the Big Bang.
The Nobel Prize-winning physicist Roger Penrose proposed in his 2010 book Cycles of Time: An Extraordinary New View of the Universe that galactic formation is a cyclical (rather than linear) process, and that the Big Bang is actually a transition between the end of an old universe and the beginning of a new one.
However, most attempts to imagine what happened before the Big Bang are met with disdain in intellectual circles. As astrophysicist Ethan Siegel wrote in 2023 for Big Think, there is no “evidence of a universe before the Big Bang.” If our universe came from a former one, whether through Eternal Inflation or otherwise, traces of that earlier universe should be seen in ours, as well as in the structures of our galaxies and the CMB. But they don’t, which means that the Big Bang was, as far as we can tell, the beginning of the beginning.