You have probably heard of the big bang as an event that gave rise to our universe. It occurred 13.8 billion years ago according to cosmologist. Basically , Big bang tells us that our universe evolved from very tiny dense ball to gigantic space. This sounds really ridiculous and pointless to many people. Is this theory fallacious or veracious?
HISTORY OF BIG BANG
In 1608, A Dutch spectacle maker named Hans Lipperhey invented an instrument that could magnify any object up to 3 times.
This was the first telescope-like device in the history of humankind. However, Historians are not absolutely sure who invented the telescope.
When the Italian Physicist/astronomer Galileo Galilei heard about Lipperhey’s invention, he immediately set out to make his own instrument in 1609. Finally, He comes up with a device that could see the volume of stellar space magnified 27,000 times .
Galileo Galilei became the first person to ever point the telescope in the sky.
After spending many hours with the telescope , he found that planets don’t rotate around the Earth but the Earth itself rotates around the sun. He supported the Nicolaus Copernicus Heliocentric model.
For the sake of religion, Churches didn’t accept the Heliocentric model and sentenced Galileo to whole life imprisonment.
In the 1800s , astronomers experimented with a device which could divide light into spectrum of its components wavelength called as spectroscope . It showed that light from specific material produced same distribution of wavelength unique to that material . Through wavelength distribution (spectrograph) one could easily figure out the elements in a light source .
Meanwhile, Austrian physicist Christian Doppler discovered the relation of the frequency of wavelength with that of relative motion between source and observer. This phenomenon is called the Doppler effect.
Light is also an electromagnetic wave. Astronomers discovered that some stars had more light falling into the red side of the spectrum than they expected. They came to the conclusion that as stars move away they shift to the red end of the spectrum because that end has longer wavelengths. This is called redshift. A star’s redshift theorized that the stars were moving away from Earth.
At the beginning of the 20th century, American astronomer George Ellery Hale set up a huge and advanced observatory of that time, popularly known as Mount Wilson observatory. In 1917, He set up a 100-inch telescope and observed numerously patterned as well as patternless luminous clouds. They were actually nebulas, but nebulas hadn’t been discovered then. Hale invited numerous astronomers and cosmologists to study about this. Edwin Hubble was invited too.
Edwin Hubble really was a pretty good observational astronomer. Hubble spent several nights looking for discoveries of galaxies and nebulas. Through the standard candle method, Hubble successfully was able to measure the distance of Andromeda nebula which wasn’t precise due to lack of technology. However, Hubble made a revolutionary statement that Andromeda nebula itself was a galaxy and was out of borderline of milky way galaxy. Hubble concluded that we are addressing galaxies in terms of nebulas which is not scientific. Hubble turns out to be right.
In 1920 ,Edwin Hubble noticed something even more fascinating . He observed that the further away a star from us ,the faster it appeared to move from us . Hubble conceptualized this with universe itself was expanding rather than being motionless . That was the time when concept of big bang theory was coined . He came to conclusions that billions of years earlier the universe would have been unimaginably tiny and dense .
Hubble discovery wasn’t appreciated at that time not even by a genius like Albert Einstein. Moreover, the instrument wasn’t advanced enough due to which Hubble’s constant ( relation between the celestial body’s velocity and distance from observer ) was not accurate enough. According to Einstein, he described the universe was static which doesn’t change with time. Einstein turned out to be wrong right after he discovered the ‘General Theory of Relativity ‘. After completion of his theory, Einstein was surprised to discover that the universe actually seemed to be expanding. Einstein admitted that he was mistaken.
MISCONCEPTION ABOUT BIG BANG
Big bang theory is widely accepted by many scientists, cosmologists including philosophers too . Mainly , People just misunderstood it .
1. No origin explanation: People subject big bang with a theory that describes the origin of the universe but is not so. It doesn’t clarify what initiated the creation of the universe . Neither it explains what came before the big bang nor where big bang happened or what existed before time. It just endeavors to explain the initial stage of the universe . It is more like the evolution of the universe .
The concept of space and time came after big bang . According to Einstein’s Theory of Relativity ,it describes space and time as a kind of interconnected fabric for the universe . So ,What existed before time makes no sense . When there was no time how one could use the word before or after .
2. Not really explosion: It is easy to explain big bang theory with a kind of explosion. This is just for understanding, more like explaining to a kid . It doesn’t explain the explosion but rather about expansion, an expansion possibly faster or nearer to the speed of light. Neither in philosophical nor in the scientific sense it is an explosion. The name big bang doesn’t refer to an explosion . Well, to be honest, then you can blame the name.
3: Instant life : Right after big bang everything wasn’t formed all of sudden . It took billion of years .
WHAT REALLY IS BIG BANG
Big bang describes about the expansion of space itself . It is not like the explosion which resulted scattering of matter, energy ,and space .
Singularity : At the very beginning of the big bang ,all of the matters ,energies were condensed in a tiny ball of infinitely small mass ,infinite density and infinite temperature . This refers to as Singularity.
THE FIRST SECOND
This will describe the event that took place within a second of the big bang.
t = 1 x 10 ^ -43 seconds
t refers to the time after the creation of the universe.
At the earliest moment of big bang ,the universe was so small that law of classical physics didn’t work out to be perfect. Instead, Quantum physics were in play which deals with particles on sub atomic scale.
At t = 1 x 10 ^ -43 seconds, the universe was unimaginably small, dense, and hot. This homogenous area of the universe spanned a region of only 1 x 10 ^-33 centimeters. The universe consisted of swirling sea of subatomic particles that cause matters and energies were inseparable at this phase. The temperature of this universe was 1×10^32 degrees, Kelvin. The four governing forces of the universe were all part of a unified and single force.
The forces are :
Strong nuclear force
Weak nuclear force
• Inflation : Within a tiny fraction of second , the universe expanded rapidly and cooled down . This refers to as inflation.
At around t = 1 x 10^-35 seconds, matter, and energy decoupled. Baryogenesis took place resulting in the baryonic matters (matter that we can see). Dark matter is not visible but it exists we know. During baryogenesis, the universe filled with a nearly equal amount of matter and anti-matter. However, there was more matter than anti-matter. so, most particles and anti-particles annihilated each other, but some particles survived. These particles would later combine to form all the matter in the universe.
At t = 1 x 10^-11 seconds ,the unified force started to break down into components .The forces were splitted off. Even in this phase the universe was too dense for light to shine within it .
0.1 second after the beginning of big bang . The universe continually expanded and cooled down . The neutrons and protons were formed because of bonding of sub atomic particles formed during Baryogenesis .
After a complete one second, the universe was stable enough to form the nuclei of lighter elements like hydrogen and helium in the form of isotopes through a process called nucleosynthesis. But the universe was still too dense and hot for electrons to join these nuclei and form stable atoms.
THE NEXT 13 BILLION YEARS
After 100 seconds, the universe temperature cooled to 1 billion degrees Kelvin. In this phase, the universe was approximately filled with 75% hydrogen nuclei and nearly 25% helium nuclei. The temperature was still not stable enough for electrons to bond with nuclei. The photons were continually forming because of the collision of electrons with subatomic particles like positrons. The universe was too dense for light to shine inside of it.
After about 56,000 years, the universe had cooled to 9,000 degrees Kelvin.
After another 324,000 years, the universe had expanded enough to cool down to 3,000 degrees Kelvin . Finally, protons and electrons could combine to form neutral hydrogen atoms
After 380,000 years, the universe became transparent and allowing light to shine throughout. This light/radiation would be later identified as cosmic microwave background radiation.
After some 100 million years ,the universe continued to expand and cool.
After some (100 – 200) million years, the stars began to form galaxies through clustering together. Some of the stars exploded ejecting matter across the universe, while some became a supernova. The heavier as well as lighter elements were all formed.
Now we are in the present state of our universe. The temperature of the universe is just a couple of degrees above absolute zero in essence 2.725 degrees Kelvin. This universe is way bigger than one can imagine. Universe vastness is indescribable. The universe is continually expanding. Scientists found that the universe is at least 250 times larger than the observable universe, or at least 7 trillion light-years across.
DID BIG BANG REALLY HAPPEN ?
1. Cosmic Microwave Background Radiation ( CMB)
Our eyes are just capable of seeing the electromagnetic wave of a wavelength that lies under visible region and light falls into the visible category.
In 1964, astronomer Arno Penzias and Robert Wilson were working on radio telescope which could detect microwaves and radio waves coming from space. When they pointed telescope out of Milky Way galaxy, they found something suspicious. They observed heat and radiation rather than vacuum and absolute zero temperatures everywhere from space. They thought it to be an instrumental error but surprisingly they found evidence to big bang theory. The radiations were microwaves which were the aftermath of the big bang. It is the remnants of intense energy formed emitted by a primordial fireball in the big bang. Unlike the light coming from a star, the Cosmic Microwave Background is the same wherever you look, and wherever you are in space.
If somehow we are able to make all the stars nonluminous ( completely dark ), we can actually see the dim red light. This light is now present in the universe in the form of microwaves.
2.Expansion: The universe is still expanding. We can see the galaxies moving afar from us. Light is also made up of waves. so the same is true of very fast-moving objects like galaxies. If a galaxy is moving away from us, the light waves are stretched. That makes the light seem redder. The faster the galaxy is moving, the redder the light. By the application of the spectrograph and Doppler effect, we can easily prove the universe is expanding.
3: Billion years old: Light from objects that far away take longer to reach than the object nearby. If an object is a million light-years away, we are seeing it as it looked like million years ago.
Using our modern astronomy, we can view objects many billions of light-years away, close to the time of the Big Bang. If the Big Bang did happen, then we’d expect those distant views to reveal clouds of gas that have not yet turned into stars and galaxies.
Astronomers have recently found gas clouds like this in the distant Universe in which some of them are 12 or 13 billion years old. Even at this incredible distance, we can tell what they are made of by using a technique called spectroscopy to analyze components of the wavelength of light that pass through them.