You might have heard of the Big Bang Theory. Nope! Not the TV show where a couple of geeks rent a room across a blonde bombshell.?
It's a theory which models the event which began our Universe. Our Universe, according to this cosmological model, started with a Big Bang nearly 14 billion years ago. It is the energy from the Big Bang which led to millions of years of various reactions finally leading up to the galaxies, the stars, the planets, and the modern Universe as we know it!
Our cosmological interest began in the ancient times, like in the BCE era. The Indus Valley Civilization had used astronomy to track the Sun and the Moon to arrange their calendar. Like how is one supposed to figure out when long weekends occur, otherwise! In the Indian subcontinent, recorded astronomical studies were done by Aryabhatta. Astronomy also found more than a passing interest in the ancient Greek, Chinese, Mayan and Egyptian cultures, followed later by the Middle Eastern and the Western European cultures.?
Timeline of the origin of the universe since the Big Bang
But fast forward to the relatively modern times of exactly a hundred years ago and Einstein came up with the General Theory of Relativity which may as well have been written in ancient script, undecipherable by us common folks. But as far as the high IQ elites are concerned, General Relativity provides a framework to model the entire Universe on – details of how, what, when and where.
When Einstein sat down to solve the General Relativity (GR) equations, he looked for a universe that is static, a notion that he then firmly believed in. And what that meant was the universe is just there, neither expanding nor contracting. Like if our galaxy, the Milky Way, had an address of 221B Baker Street, it would remain so a million years from now.?
Here's where the problem came about. More than a decade since Einstein's GR solution, Hubble, a very smart guy and the father of a constant named after him, observed that galaxies are moving and moving farther away (layman speak). This was followed by some rather cool calculations by a Belgian priest and part time scientist, George Lemaitre who provided an expanding Universe model in GR. In other words, he found that a static universe is unstable and would collapse, thanks to its own gravity. A static universe may not be the right answer. Rather a dynamic one could be! So there is a distinct possibility that the Milky Way could move to 222B Baker Street, years from now. Hmm! Here's a doozy to confound Sherlock! Alas, it didn't confound Einstein anymore and he later relented that there was no special reason that the universe should be playing London statue.?
It implies that if the universe is expanding, it had to have begun expanding somehow. And that event which started the expansion must have been a massive one releasing immense energy for it to be continuing to expand still. Funny story is that this event was actually christened by opponents of the theory of the expanding universe. The name, The Big Bang!
Obviously not by hiring a bunch of people to work shifts to keep an eye on the moving galaxies! Instead try this for clarity's sake. Your pressing iron, when it gets hot, activates the surrounding molecules in the air. This activation propagates as a thermal radiation. And that shows a temperature reading.?
So, if Big Bang was an energy releasing event, there would be a remnant of that energy still radiating through space. This thermal radiation, carried by waves, should have a temperature reading, cooling down as the universe expanded. Scientists calculated this and zeroed in on a space 'taapmaan,' 2.7 Kelvin or about -270?C. And this background wave, in space, was called the Cosmic Microwave Background Radiation (CMB).?
Of course, that was the theory. No one was going to really buy it until someone clever came up to show that some proof existed. Here's where the story of pigeons come in!
Pigeons did play a cameo in proving the Big Bang Theory.?
In 1964, two Bell Laboratory scientists, Penzias and Wilson, were on a mission to build a super sensitive radio antenna for astronomy and satellite communication experiments.
The radio antenna that picked up CMB radiation. NASA
If any one of you, pre-millennials, remembers our roof top antenna televisions, you would also recall the noisy static that would haunt your Tv screens until the signal finally hit those aluminum antenna rods.?
Well, in this case, with such a huge sensitive radio antenna at their disposal, the two super smart scientists were somehow unable to get rid of a constant static background no matter where they directed the receiver.?
One of them suggested that the pigeons flying around and constantly pooping on their sensitive antenna could be distorting their signals. They cleaned up the shit, excuse the language, and re-tried their experiment. But that damned static stayed!
They realized that the static was causing the equipment to pick up a constant background temperature of about 3 Kelvin. Could it be?
Yes. This was the same Cosmic Microwave Background being picked up by the antenna. And no matter which way they looked, in space, it stayed the same.?
An interesting fact is that a very small portion of the static, on our household rooftop antenna TV, is also comprised of CMB radiation!
memecenter
Indeed it was a eureka moment. Penzias and Wilson were given the Nobel award, in Physics. Part of it probably because cleaning pigeon poop showed massive dedication towards science.?
So what started off as a still picture, of our Universe, turned out to be ever expanding. And the expanding universe started with a Big Bang. But that's not the end. The aftermath research has shown that Einstein's GR has room to include yet another feature. Another solution, in the framework of General Relativity, shows us that not only is the universe expanding, it is accelerating! That is, the universe is expanding at an ever increasing rate! Why? Because of something called The Dark Energy. But we will leave that discussion for later.
Until then, gutur gutur!