EINSTEINS IDEA ON GRAVITY WRITTEN BY LORDSONROY - Anna University Internal marks 2018

GRAVITY
The term”GRAVITY” has puzzled many people for centuries. But the first person to provide an answer to this question was Newton. When an apple fell on his head he wondered why the apple is falling down. He then worked on the subject and got the results on what we call as gravity. He said it is a force that exists between two bodies. He provided us with equation that enabled us to calculate the amount of force exerted on a body,

But he does not explain what, how and why gravity is caused. His theory also allowed us to calculate the behavior of matter to a certain limit.untill Einstein’s period no one was able to give a correct reason for gravity.Untill that newton’s idea on gravity was thought to be correct. Everything changed when Einstein published his theory of relativity.

EINSTEINS IDEA ON GRAVITY
Einstein with his concept of space time curvature rocked the world of physics. He said that mass distorts space thus creating space-time curvature. We think that gravity is just a force that holds us on our feet. He simply rejected the idea that gravity is just a force. But we feel gravity as a force and we cannot simply reject the idea of force and accept gravity as space time curvature. Because it is weird to imagine gravity in Einstein’s way and at the other hand have been brought up by the idea that gravity is a force as in our text books. But it’s time to get an update on gravity.

As per the concept of space time curvature gravity works on the two rules
• A particle travelling in a gravitational field will take the shortest path
• A particle travelling in a gravitational field will travel along a straight path
It is hard to accept the two rules but in this article I will try hard to make things simple and easier. Gravity
CASE 1:
Consider that you throw a ball. It will make its path through air and hit the ground but what’s weird about that .The fact is that it has taken the shortest path. But you think that everything is normal and you would not experience any difference. This is normal in the case of a ball. But it’s totally different when gravity is stronger so that not even light can escape from it.in the case of the ball it is subjected to a little gravity so nothing extraordinary happens. The below figure represents a ball thrown from point a.The ball travels and hits the point b.The path is a projectile motion. In reality the ball goes straight. No curved path but we see a curved path of the ball. This is because that space time is curved Gravity
Now in the below figure the real path of the ball is shown Gravity
This is because we cannot see the dimensions like space and time and our brain should should somehow process it so it gives us a curved path. (NOTE: This is because of our brains inability to process info beyond a certain limit and as per some reports our brain only process only 10% of the data it gets).that’s the reason for the curved path.

CASE 2:
In this consider a beam of light travelling straight into a black hole (a black hole is a dead star but with a very high gravity. Not even light can escape from it) when the beam reaches near the black hole its bends and moves into the blackhole.This is because it takes the shortest path.(it is the first law and not well explained in case 1).so if you think gravity as a force it will be pulling the object to ground. But as per space time curvature it is not a force so it should be going forever (i.e.) a ball thrown Gravity
Will be travelling and do it will not hit the ground. But as I have mentioned earlier that gravity is space time curvature it is the amount of time of the object (i.e.) when we throw a ball after an amount of time the ball will fall down because the time for the ball to be in motion expires so that it fall down and it is not the gravitational force which pulls it down.

Post Author : Lordson Roy
College : Bethlahem Institute of Engineering
Year : Third year IT (2013)