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It will go back 100 years ago. Physics then stood on two classical theories. One is Newton's motion theory. Another Maxwell's electromagnetic theory. Newton's theory of gravitation is one of the foundations of natural science. However, the sub-continental theory is not beyond the theory of Newton's fundamentalism.

Before the relativity was released, scientists distinguished space and time. Einstein said, space and time are no different. The place will look at one place. Earlier there were three dimensions of the material. Length, width, and height. These three levels of space. Since the space station is the same entity, so the level of materiality increased. It is a period of time or time. The term 'place' has gained a special status in physics.

Einstein said, the whole universe is standing on this stage. Let's find out about this. Where are the planets, stars, galaxies of the universe are standing?

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Many people say, in space or in the universe. What is this universe or space?

Before that scientists used to say its a space. Einstein said, just saying spaces would be wrong. That's actually the spacetime.

Another famous formula came out from special relativity. That is the power of the empowerment. It came out of this equation, mass and energy are not identical bodies. The mass can be transformed into energy. Likewise, it can be possible to fill the energy.

Einstein did not sit on expressing special relativity. This theory did not understand the physics. No theory has been said about the gravitational force. Newton's epic has already been told. With Newton's theory, the direction of the planets and the stars, the rotation of the Earth, the mechanics, etc. were well explained. But there were some flaws in the gravitational formula. The time was not talked about. How long does it take to take action of a gravitational force on another object?If there is a change in the mass of both of them, then their gravitational force will change, how long will it take to change that?

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Let's talk about the earth and the sun. The sun's distance from Earth is roughly 150 million kilometers. Let's suppose that another big star in the space disappears and stumbles over the sun. Unable to cope with the sun, it moved a little away from its position. As a result, the difference between the distance between the earth and the world is fading. As a result, the quality of the gravity force will also be transformed.

But when the world has realized that the force of gravity has changed? Is it as soon as the sun departs?

Or later?

How much later?

Newton's gravitational formula says that if the difference is distinction, then the attraction force of two object will be different. So, when the sun departs, the world will understand it immediately.


Then the gravitational attraction is a Remedies?


That means without spending the time, the message will spreading billions of kilometers away?


Is it possible?

Here is the main problem. But in Newton times, no one thought about this crash.

A few more questions was passing through in Einstein's mind. What is the source of gravitational force? Gravitational force acts as an object inside the object. The power and magnet attracts religion. But those two forces have the ability to deteriorate. But the gravitational force only attracts. There is no rebel power.

But why?

Since 1907, Einstein lives in the Bern city of Switzerland. There he was a clerk in the patent office. One day, He sitting in the office, a thought came to her mind. Which he said, the happiest thought of his life.

Suppose a man is standing inside the elevator. The elevator has hundreds of feet above the ground. Suddenly, if the elevator ropes are torn off. Then the elevator and the inner man will be falling down freely. The acceleration of them will be equal to gravity acceleration. The man will not feel the weight in that time. Anything that is falling freely from above seems to be a weightless person until it touches the soil.

When two different objects are falling down from the same height Then their acceleration will be equal. They touch the soil simultaneously.

Galileo discovered these formulas of declining objects. These formula mathematically proven by Newton. That is, there is no relation of mass on the velocity or acceleration of a declining object. But the gravitational force of the earth is responsible for the declining objects. The gravitational claim is that the gravitational force is dependent on the mass.

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Einstein attempted to attract the attention of Earth on the fallen object and gravitational force with a thread. Newton showed that the gravitational field of the Earth is responsible for the acceleration of the falling objects. Einstein thought a little differently. Object is accelerated due to gravity force.


Where the gravitational force is missing, if any object is accelerated, then what would be the gravitational force. Einstein calculated that, if there is no gravitational force, if a lift is accelerated mechanically, then the artificial gravitational field is created inside the elevator.


Then Einstein began to study all the mysteries of the gravitational force. In 1915 he published the special theory of relativity. It was said that the object's gravity is not responsible for the gravity force. Gravity Force is the game of space-time geometry. He calculated that there is a huge presence that binds place-times.


Suppose, a sheet. It is tied in four pillars. In this case, the sheet will also be tilted like a flat surface. After that an iron ball was kept. The middle of the sheet will then lie down in front of the ball. Now let's roll one glass to one side of the sheet. It will gradually move forward in the middle of the sheet. Where the iron sphere is there Then go around the sphere and turn around. Once upon a time, you will get hit with the iron sphere.



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Why is this happening?


Because the iron sphere baked middle of the sheets. So rolling over the ball on the sheet, it does not get flat paths to run. His way has been twisted. So he went on a bent road to the sphere.


Space time can also be compared to those sheets. The presence of heavy objects such as earth, sun, stars, black hole, etc. binds place time. When another light object approaches heavy objects, it seems that heavy objects attract light objects. The way the iron sphere was attracted to marble on the sheets. But there is a difference of place with the sheets. Space-time four-dimensional And the floor of the sheet is two-dimensional. Therefore, the space will bend heavy objects to the four levels.


This curvature of space-time is the source of gravitational force. But it was not being explained with our common Euclidean geometry. Einstein then went to Marcel Grassman, his mathematician friend. Grodman gave him a search for curved geometry founded by Carl Gauss and his student, Bernanke Reiman.


With that geometry, Einstein resolved the general theory of relativity. As well as gravitational force is also solved. In 1919, a group of astronomer Arthur Eddington gave evidence of the first general theory of relativity.
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(To be continue...)

Thank you for taking the time to read this post. Your COMMENTS and UPVOTES are highly appreciated.

Check other parts of this Series here:

1. Black Hole; Part-1 : History seen back

2. Black Hole; Part-2 : Gravity Background

3. Black Hole; Part-3 : Newton's Gravitation

4. Black Hole; Part-4 : Newton's cannon and earth's escape-velocity

5. Black Hole; Part-5: Light burning

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