A force by definition is a push or pull that an object exerts on another, causing it to experience motion or deformity. Everything in the universe experience some kind of force that react with it in every second. These forces can be grouped in four major fundamental units and termed as "the four fundamental forces of nature".
The four fundamental forces of nature are the most major forces that govern the behavior of everything in the universe and they cannot be further divided into any other basic forces. They can also be termed as the fundamental interactions. The are the simplest unit of force in which other forces present in the universe are built on.
These forces include:
- Gravitational force
- Electromagnetic force
- Weak nuclear force
- Strong nuclear force
Gravity
In the elementary stage, gravity was defined as the force that tends to pull all object towards the center of the earth. But the earth is not the only system that has or experience the influence of gravity, in theory, everything in the universe having mass will experience gravity.
Gravity is thus a force that that attract two or more objects having mass together. Gravity surrounds us, it responsible for pulling all objects having mass towards earth's center example when you throw a ball into the air, it returns to you because of the earth's gravity. The earth is surrounded by a gravitational field and this force of gravity on the ball is what pulls it back to the earth.
Gravity is also what binds planets in an orbit around the sun. Gravity by nature is too weak to be noticed unless at least one of the masses is very large. As described by Einstein's general law of relativity, gravity comes as a result of space-time curvature. If an objects has more mass, it will create more curve in space-time and consequently will have more gravity. That is exactly why the gravitational attraction between planet's orbital around the sun appears to be stronger because the sun has a relatively greater mass, creating more space-time curvature(as Einstein explained) and thus more attractive force.
Newton was the first scientist that discovered the force of gravity while watching a falling apple from a tree and asked why the apple fell. He later postulated his laws universal gravitational law, stating that the force of attraction between two bodies of mass m1 and m2 is inversely proportional to the square of their distance R between their centers and is directly proportional to the product of their mass.
This can be represented mathematically as:
F= Gm1m2/R^2
Where
G= the universal gravitational constant
m1 & m2 = the masses of the two bodies
R = the distance between them
Overview of gravitational force
-It always tend to attract objects, it never repels them.
- It cannot be modified, absorbed or shielded against.
- It has an infinite range, thus it capable of holding planets, stars and galaxies
- It hypothetically uses gravitons as the mediators
- Mass acts as the main source.
Electromagnetism
The word "electromagnetism" contains two terms, namely electricity and magnetism. It was long thought that electricity and magnetism were separate forces, ideas changed as Einstein's law of relativity describes electricity and magnetism not as separated forces, but as inter-related phenomena. Electricity gives rise to magnetism and vise-versa.
Electromagnetic force is a force that acts between electrically charged particles (electrons, protons, ions, photons) and it's so named as it exhibit both the property of electricity and magnetism.
It is the force that causes like charges to repel each other and unlike charges to attract each other. These phenomenon of attraction and repulsion is what binds electrons close to their orbitals, as they are attracted to the positively charged neutrons in the neucleus.
Light also is an electromagnetic wave, that undergoes continuous oscillation from electric field to magnetic field at right angle to each other.
Electromagnetic induction is also a phenomenon of electromagnetism, where electricity can be generated using changing magnetic field across a coil of conductor.
So as we can see, electromagnetic force plays a vital role in our day to day living.
Overview of electromagnetic force
Weak nuclear force
These nuclear changes are very vital for the working of the universe and even life on earth. For example, nuclear fusion is responsible for generating energy from the sun and other stars, where hydrogen is converted into helium.
Overview of the weak nuclear forces
- It is the third strongest fundamental forces of nature having an infinite strength of 10^25
- They occur at a very short range as it only acts upon sub-atomic particles. Hence, it has a infinite range of 10^-18
- W and Z bosons acts as the mediator
Strong nuclear force
The strong nuclear force is by far the most strongest and complex force in the universe. It only act upon sub-atomic particles in the nucleus. The atomic nucleus is made up of protons and neutrons, the protons possesses a positive charge while the neutrons are electrically neutral. The protons which were supposed to repel each other because of their like charges are tightly binded together in the nucleus by the action of a force called the strong nuclear force.
The electromagnetic force couldn't possibly keep the nucleus of an atom together, because it is much too weak, and the protons would simply repel one another and fly, because they are all positively charged, and we know that two positively charged particles won't attract each other. So there needs to be a stronger force, and that just happens to be the Strong Force. This force is also responsible for binding Quarks and Gluons into Protons and Neutrons.
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