Today we look at the revolutionary contributions of Albert Einstein to Physics, and to society in general.









WHAT IS GRAVITY

But a few dared to ask why, and fewer bothered to answer.

The answer to this question was proposed by one of the greatest minds of the species, Sir Issac Newton

A portrait of Sir Issac Newton by Godfrey Keller





Newton's idea of Gravity was as follows,

he thought there exists a mysterious force between bodies which was directly proportional to their masses and inversely proportional to the distance between them. So more massive the body, higher would be the Gravitational Force, and as the distance increases, Gravity would start decreasing in strength.





Newton's laws were revolutionary, his book Philosophiae Naturalis Principia Mathematica (Mathematicial Principles of Natural Philosophy)is still regarded as one of the most influential works in Science.









Fun Fact: In the third volume of his book , Newton had made a calculation error. Instead of taking a value as 10.5, he took it as 11. This went unnoticed for 300 years until a 23 year old student noticed it in 1987.





Newton provided some answer to the questions of Gravity, but he couldn't explain what this mysterious force is. This bothered him as well, but he left the answer as God's work.Nobody could explain how the Sun reaches out to Earth millions of miles in empty space and keeps it revolving in circles. The answer came from a clerk at the patent office, Albert Einstein.





WHAT REALLY IS GRAVITY.

Einstein at age 25





Einstein's ideas were revolutionary. According to Newton, space and time are absolute. Imagine all of the Universe as a play, a stage play where space is the stage.Einstein proposed that the stage is part of the play too, that space and time are not static, but dynamic . This is the most beautiful and unique thoughts in the history of humankind.

In this new picture, The Sun being massive bends the spacetime curvature and the Earth travelled along a straight line in the the curved surface, thus moving in roughly circular orbits. Since then, his ideas and equations have been tested a number of times, and each and every time, it has been found to be true.





Ripples in Spacetime.

Imagine that you throw a stone in a pond, you will observe that from that point , ripples emerge outwards and spread across the pond.

In an analogous way, when two massive bodies collide, ripples will be formed on the spacetime curvature.

LIGO (laser interferometer gravitational wave Observatory) was successful to detect these Gravity waves when two massive black holes collided. This further confirms his theory, and the detection of Gravitation waves won the Nobel Prize.





Light bends while travelling in Space.

Another prediction of Einstein's theory was that light travelling close to a massive object would appear to be bent . The actual picture is, that space bends and light travels through the curved space and thus appears to be bent.

Arthur Eddington, a British Astronomer set out to prove this idea.

Sir Arthur Eddington





Fun Fact: Ounce during an interview, the interviewer said that there appears to be only 3 people on Earth who understand relativity, to which Eddington replied"I'm wondering who the third person is?"





This hypothesis is difficult to test, as the stars behind the sun are barely visible, because of Sunlight. So during an eclipse in that period, this was tested and the Star behind the Sun did appear to be shifted from where it usually is.





Speed of light is constant.

This was one of the most intriguing questions in physics, how can speed of light be constant for any observer, whether at rest or moving. Speed is distance over time. So for the speed of light to be constant, space and time couldn't be static, they had to be dynamic. In fact, this realization, that time can slow down or speed up, is what makes GPS possible. Without the relativity correction, the position indicated by the GPS would be way off.

The faster you move through space, the slower you move through time.





Fun Fact: Your feet are much more closer to the Earth than your head , so your head ages faster than your feet, your head is a little older than your feet . That difference, wouldn't be tooo long, it might be a very very very small difference, but it exists.





Relativity is not an easy concept to grasp, it took a decade for Einstein to come up with it. The point of this article is to show you, why things other than survival, are worth doing. Thinking not for the sake of getting rich , or for awards or recognition, but for the sake of thinking itself, for understanding nature and contemplating the Universe, is itself a gift .This species of ours, human beings, we're not the fastest, strongest, but we are the smartest , we think , we wonder and that is what makes us , Human.





Einstein was ounce offered the Presidency of Israel, he refused saying, and I quote





"Equations are more important to me, politics is for the present, but an equation is for eternity"





Article by: Shanawaz Shaikh

( F.Y.BSc )





If I throw a stone towards the sky, it falls down. If I toss a coin , it comes back into my hand , if I propel a rocket outwards with a certain speed, it reaches a maximum distance and then continues to fall down on Earth. We know that this is what happens, and this is fairly intuitive.