What is Big Bang Theory?
A theory that is accepted by scientists which explains the origin of the universe. This term is misunderstood by many people, It doesn't explain What existed before the origin of the universe. It explains the expansion of the universe. Before the big bang, scientists believe, the entire observable universe, including all of its matter and radiation, was comprised in to a hot dense mass just a few millimeters across. In that state, all 4 fundamental forces of nature ( gravity, electromagnetism and the so called nuclear strong and weak forces) all in one condensed hot dense tiny place. An explosion of that tiny dense particle which we call "The Big Bang" gave birth to the universe. It started expanding the moment it explodes and its continued its journey of expansion for ever.
Lets take a look at the 4 fundamental interactions of nature:
In 1687, Sir Issac Newton, a theoretical physicist from England defined its behavior with his famous law of universal gravitation. He published his finding through his work "PRINCIPIA MATHEMATICA", one of the most widely influenced book in science history. Newton hypothesized that the gravitational force between any two objects is directly proportional to their mass and inversely proportional to the square of the distance from their centers. If m1 and m2 are the masses and d is the distance, then the force (F) is given by the formula
F = km1*m2 / d^2
Where k is universal constant.
Newtons theories about gravitation was modified by Einstein in 20th century with his revolutionary theory "Theory of Relativity". In this theory, he stats that, the nature of force exerted by gravity is same as the nature of force exerted on an any object that undergoes acceleration.
This is called "Principle of Equivalence". He also stats that gravitational force cause distortion in space and time. It was later validated and confirmed through experimentation.
Gravitation is one of the most studied phenomena in physics. There are questions like, what is gravitational force constitutes of? Why gravitational force exists between objects of non-zero mass, whats the scientific reason? on what speed gravitational force travels?. Till today, there are no clear answers.
Speed of gravitational force, how fast the gravity travels? According to newton, gravity is instantaneous. But Einstein, in his revolutionary theory stats that nothing can travel faster than light. According to him, gravity travels with the speed of light. Still today, there some debate going on between scientists stating that Newton were right and Einstein was wrong with some experimentation.
Messenger Particle: Graviton
Messenger Particle Mass : 0
Electromagnetism
Its one among the four fundamental forces of nature and also the most understood force among all. As the name suggests, Its the production of magnetism from electricity. But, there is more to it. It is not a topic to finish in one line of statement. To get a clear picture about electromagnetism, we have to go to sub-atomic level first.
Lets take a look at an atom first. An atom constitutes of proton, electron and neutron. Proton and neutron forms the nuclei of an atom. Proton carries positive charge, electron carries negative charge and no charge for neutron. So, its now clear that two of the particles(protons and electrons) of an atom carries electrical charges(+ and - ). These electrical charge between the electron and nuclei of an atom creates a force that we call as "electromagnetic force" that makes the atom binds together and ultimately forms the matter. So, it is now clear that electromagnetic force is caused by the electrically charged particles and that makes them attract or repel each other.
When electrons are put in to motion, it creates magnetic field. I think, now you can understand what's the reason behind the emergence of electromagnetic force. Inside an atom, electrons are always revolving around the nuclei. Its always in motion. It jumps between the orbitals. so, this creates a magnetic field, which makes the charged particles to attract or repel each other. So, we call this force as Electromagnetic force.
When electrons are made to oscillate, it creates electromagnetic waves, which is the result of radio waves, x-rays, visible light, etc depends on their frequency.
We saw how electromagnetism behaves at sub-atomic level. Now lets go on to larger scale.
We know that electrons are electrically charged particle and carries negative charge. We also know that when electrons are put to motion, it creates magnetic field. When large number of electrons are allowed to move through a conducting material like coil, it creates magnetic field around the coil. In other words, when current is passed through a coil, it creates magnetic field around the coil. This phenomenon is known as electrodynamics. (i e, creating magnetic field with the flow of electrons). The intensity of the magnetic field can be increased by two factors, 1) increase the number of winding of the coil 2) Increase the flow of electrons.
The other way around is also possible, that is, creating electricity with varying magnetic fields. When a permanent magnet is put in to motion near a conducting material like coil, it makes the electrons flow inside the coil which we call as "Current", a current is induced in the coil. This phenomenon is known as Electromagnetic induction.
Messenger Particle: Photon
Messenger Particle Mass : 0
Nuclear Strong Force
Among all 4 fundamental forces in physics, nuclear strong and weak forces are less understood and unfamiliar forces. Strong force keeps the quarks together inside the proton and neutron. It is also responsible for keeping the proton and neutron together inside the nuclei. In other words, it glues the elementary particles together. Unlike gravitation and electromagnetism, its range is very short. It acts only inside the sub-atomic level. Most importantly, Its the most strongest force of them all.One peculiar aspect of this force is, as the distance increases, the force increases. This is the fundamental reason why the protons and neutrons inside the nuclei is intact.
Neutrons carries no charge, but the force gets repulsive when there are more than one proton, since like charges are repulsive. But the strong force overcomes the repulsive force and keeps all the protons and neutrons together inside the nuclei.
Strong force range is very short. Like charges are repulsive. I know what you are thinking, Whats the role of electromagnetic force here? why electromagnetic force didn't overcome strong force?. Yes, Electromagnetic force overcomes strong force if the distance is more. Both particles must be very close, about the diameter of a proton, in order for the meson particle exchange to happen. In order to produce this nuclear force, particles must be travelling at a very high speed( under extreme temperature ) or under immense pressure. Neutrons also helps to reduce the repulsive force of protons. Since they didn't have any charge, their presence inside the nuclei separates the protons from each other and also they have the ability to exchange meson particles, these properties makes the neutron to deliver additional attractive force inside the nuclei and intern helps the strong force to overcome Electromagnetic force and keeps the nuclei intact.
Meson particles were later called as "pions"
Gluon particle exchange/interaction happens only between the quarks present inside the protons and neutrons.
Messenger Particle: Gluon
Messenger Particle Mass : 0
Nuclear Weak Force
This force is the most unfamiliar force of them all. I am still trying to understand how to explain this force :). In all forums I can see only one explanation, It is responsible for radioactivity. It has very short range distance scales and acts only inside the nuclei. It converts quarks present inside the proton and neutron to a different type, thus changing the element itself. It's even responsible for the sun to provide us energy. This force is carried by Boson(W+, W-, Z) energy particles. This is the only messenger particle which has mass and also the highest mass which is also the reason why its weak.
It acts on the quarks inside proton and neutrons. Interaction between the quarks happens through boson particles and this changes the quarks to another type and ultimately changes the element itself. i.e, proton can become neutron and neutron can become proton. To better understand the weak force, we have to look at whats happening inside the sun. Yes, The Nuclear Fusion, this is what powers the sun. Weak force is the ultimate source for nuclear fusion. Without this force our sun wouldn't survive. Its just the reason why sun is burning continuously for 4.6 billion years.
The following are the prerequisites of nuclear fusion process. Again, remember, this step is nearly impossible
Messenger Particle: Boson
Messenger Particle Mass : 86, 97
Out of 4 forces, 3 of them (gravity, electromagnetism and nuclear strong force) are related to attraction/repulsion. Nuclear weak force is responsible for transmutation. i.e, It converts/changes one element to another element.
A theory that is accepted by scientists which explains the origin of the universe. This term is misunderstood by many people, It doesn't explain What existed before the origin of the universe. It explains the expansion of the universe. Before the big bang, scientists believe, the entire observable universe, including all of its matter and radiation, was comprised in to a hot dense mass just a few millimeters across. In that state, all 4 fundamental forces of nature ( gravity, electromagnetism and the so called nuclear strong and weak forces) all in one condensed hot dense tiny place. An explosion of that tiny dense particle which we call "The Big Bang" gave birth to the universe. It started expanding the moment it explodes and its continued its journey of expansion for ever.
Lets take a look at the 4 fundamental interactions of nature:
Gravitation
Gravity (or) Gravitation is a force that exists on all objects in the universe, from sub-atomic particles to the clusters of galaxies. Its an attractive force that pulls together objects of non-zero mass. Take any two particles or objects of non-zero mass, gravitational force pulls them together. It acts on all distances, no matter whether its small or great.In 1687, Sir Issac Newton, a theoretical physicist from England defined its behavior with his famous law of universal gravitation. He published his finding through his work "PRINCIPIA MATHEMATICA", one of the most widely influenced book in science history. Newton hypothesized that the gravitational force between any two objects is directly proportional to their mass and inversely proportional to the square of the distance from their centers. If m1 and m2 are the masses and d is the distance, then the force (F) is given by the formula
F = km1*m2 / d^2
Where k is universal constant.
Newtons theories about gravitation was modified by Einstein in 20th century with his revolutionary theory "Theory of Relativity". In this theory, he stats that, the nature of force exerted by gravity is same as the nature of force exerted on an any object that undergoes acceleration.
This is called "Principle of Equivalence". He also stats that gravitational force cause distortion in space and time. It was later validated and confirmed through experimentation.
Gravitation is one of the most studied phenomena in physics. There are questions like, what is gravitational force constitutes of? Why gravitational force exists between objects of non-zero mass, whats the scientific reason? on what speed gravitational force travels?. Till today, there are no clear answers.
Speed of gravitational force, how fast the gravity travels? According to newton, gravity is instantaneous. But Einstein, in his revolutionary theory stats that nothing can travel faster than light. According to him, gravity travels with the speed of light. Still today, there some debate going on between scientists stating that Newton were right and Einstein was wrong with some experimentation.
Messenger Particle: Graviton
Messenger Particle Mass : 0
Electromagnetism
Its one among the four fundamental forces of nature and also the most understood force among all. As the name suggests, Its the production of magnetism from electricity. But, there is more to it. It is not a topic to finish in one line of statement. To get a clear picture about electromagnetism, we have to go to sub-atomic level first.
Lets take a look at an atom first. An atom constitutes of proton, electron and neutron. Proton and neutron forms the nuclei of an atom. Proton carries positive charge, electron carries negative charge and no charge for neutron. So, its now clear that two of the particles(protons and electrons) of an atom carries electrical charges(+ and - ). These electrical charge between the electron and nuclei of an atom creates a force that we call as "electromagnetic force" that makes the atom binds together and ultimately forms the matter. So, it is now clear that electromagnetic force is caused by the electrically charged particles and that makes them attract or repel each other.
When electrons are put in to motion, it creates magnetic field. I think, now you can understand what's the reason behind the emergence of electromagnetic force. Inside an atom, electrons are always revolving around the nuclei. Its always in motion. It jumps between the orbitals. so, this creates a magnetic field, which makes the charged particles to attract or repel each other. So, we call this force as Electromagnetic force.
When electrons are made to oscillate, it creates electromagnetic waves, which is the result of radio waves, x-rays, visible light, etc depends on their frequency.
We saw how electromagnetism behaves at sub-atomic level. Now lets go on to larger scale.
We know that electrons are electrically charged particle and carries negative charge. We also know that when electrons are put to motion, it creates magnetic field. When large number of electrons are allowed to move through a conducting material like coil, it creates magnetic field around the coil. In other words, when current is passed through a coil, it creates magnetic field around the coil. This phenomenon is known as electrodynamics. (i e, creating magnetic field with the flow of electrons). The intensity of the magnetic field can be increased by two factors, 1) increase the number of winding of the coil 2) Increase the flow of electrons.
The other way around is also possible, that is, creating electricity with varying magnetic fields. When a permanent magnet is put in to motion near a conducting material like coil, it makes the electrons flow inside the coil which we call as "Current", a current is induced in the coil. This phenomenon is known as Electromagnetic induction.
Messenger Particle: Photon
Messenger Particle Mass : 0
Nuclear Strong Force
Among all 4 fundamental forces in physics, nuclear strong and weak forces are less understood and unfamiliar forces. Strong force keeps the quarks together inside the proton and neutron. It is also responsible for keeping the proton and neutron together inside the nuclei. In other words, it glues the elementary particles together. Unlike gravitation and electromagnetism, its range is very short. It acts only inside the sub-atomic level. Most importantly, Its the most strongest force of them all.One peculiar aspect of this force is, as the distance increases, the force increases. This is the fundamental reason why the protons and neutrons inside the nuclei is intact.
Neutrons carries no charge, but the force gets repulsive when there are more than one proton, since like charges are repulsive. But the strong force overcomes the repulsive force and keeps all the protons and neutrons together inside the nuclei.
Strong force range is very short. Like charges are repulsive. I know what you are thinking, Whats the role of electromagnetic force here? why electromagnetic force didn't overcome strong force?. Yes, Electromagnetic force overcomes strong force if the distance is more. Both particles must be very close, about the diameter of a proton, in order for the meson particle exchange to happen. In order to produce this nuclear force, particles must be travelling at a very high speed( under extreme temperature ) or under immense pressure. Neutrons also helps to reduce the repulsive force of protons. Since they didn't have any charge, their presence inside the nuclei separates the protons from each other and also they have the ability to exchange meson particles, these properties makes the neutron to deliver additional attractive force inside the nuclei and intern helps the strong force to overcome Electromagnetic force and keeps the nuclei intact.
Meson particles were later called as "pions"
Gluon particle exchange/interaction happens only between the quarks present inside the protons and neutrons.
Messenger Particle: Gluon
Messenger Particle Mass : 0
Nuclear Weak Force
This force is the most unfamiliar force of them all. I am still trying to understand how to explain this force :). In all forums I can see only one explanation, It is responsible for radioactivity. It has very short range distance scales and acts only inside the nuclei. It converts quarks present inside the proton and neutron to a different type, thus changing the element itself. It's even responsible for the sun to provide us energy. This force is carried by Boson(W+, W-, Z) energy particles. This is the only messenger particle which has mass and also the highest mass which is also the reason why its weak.
It acts on the quarks inside proton and neutrons. Interaction between the quarks happens through boson particles and this changes the quarks to another type and ultimately changes the element itself. i.e, proton can become neutron and neutron can become proton. To better understand the weak force, we have to look at whats happening inside the sun. Yes, The Nuclear Fusion, this is what powers the sun. Weak force is the ultimate source for nuclear fusion. Without this force our sun wouldn't survive. Its just the reason why sun is burning continuously for 4.6 billion years.
The following are the prerequisites of nuclear fusion process. Again, remember, this step is nearly impossible
- Protons repel each other because they have same charges(+). But they must come very close to each other, about 10^-15 so that strong force overcomes electromagnetic force and keeps them together
- One of the protons changes to neutron and emits anti electron and neutrinos. It requires weak force interaction, and that happens when protons are very very very close to each other.
As I said before, the above occurrence is nearly impossible. Despite of this near impossible occurrence, sun still burning for nearly 4.6 billion years.
Nuclear fusion step by step:
- Two protons come very close to each other because of immense gravity and extreme temperature
- Strong force binds them together and weak interaction cause one of the protons to undergoes beta decay and convert them to neutron and emits anti electron and neutrinos
- This anti-electron hits another electron and makes two photons.
- 2H atom hits another proton and sticks to it and produces 3He(helium) atom
- 3He hits another 3He and produces 4He and release two free protons and during each interaction, photons are emitted and tremendous amount of energy is released
The net result is hydrogen atoms are burned to make helium. The above nuclear fusion is a very rare occurrence, but that happens in sun all the time
Messenger Particle: Boson
Messenger Particle Mass : 86, 97
Out of 4 forces, 3 of them (gravity, electromagnetism and nuclear strong force) are related to attraction/repulsion. Nuclear weak force is responsible for transmutation. i.e, It converts/changes one element to another element.
