Theory of Relativity

E=mc²

The most famous equation in the world was given to explain one of the most famous theories of the world. The theory of relativity was formulated in 1905 by Albert Einstein, a very celebrated and exceptional scientist. Einstein’s theory of relativity explains that the law of physics are the same everywhere. The theory shows that the behavior of objects in space and time can be observed, and can be used to predict everything in physics. To get a better understanding, it is vital to know what is relativity.

What is Relativity?

Relativity can be understood by a simple example of relationships. Relationships cannot be explained as a single entity. They are always expressed as duos or groups. A person is a mother or father in relation to their child and in the same way, siblings are brothers or sisters only due to each other. Similarly, when the velocity or momentum of an object is measure, it is measured in relation to something else.

However, there is no specified frame of reference.

Einstein’s Thought Experiments

The theory of relativity has been divided into two types, namely special relativity and general relativity. Einstein had various thought experiments, where he found a way around paradoxes and theories that he was obsessed with. One of his first famous thought experiment was that of measuring light from a moving train. Einstein tried everything he could think of, and nothing worked. Nearly out of desperation, he began to consider a notion that was simple but revolutionary. Perhaps Maxwell’s equations worked for everybody, he agreed, but the speed of light was always constant. When you saw a light beam rush past, in other words, it wouldn’t be important whether its source was moving towards you, away from you, or away to the side, nor would it matter how quickly the source was going. You would always measure that beam’s velocity to be miles per second. Among other things, that showed that Einstein would not see the stationary, oscillating fields, because he could not catch the light beam.

This was the only way Einstein could see to coordinate with Maxwell’s equations using the principle of relativity. At first, however, this result appeared to have its own fatal fault. Einstein subsequently explained the problem with another study experiment or thought experiment. He imagined firing a light beam along a railway embankment just as a train roars by in the same direction at miles a second.

Someone standing on the embankment would measure the light beam’s speed to be the standard number, miles a second. But someone on the train would see it moving past at only miles a second. However, Maxwell’s equations would have to look different inside the rail carriage if the speed of light wasn’t constant, according to Maxwell.

This apparent contradiction left Einstein thinking for nearly a year. But then, one morning while talking to a dear friend about the dilemma, he discovered the solution. Einstein’s revelation was that viewers in relative motion experience time in a different way meaning that it is ideally possible for two events to occur concurrently from the perspective of one viewer, yet happen at different times from the viewpoint of the other. And both onlookers would be right.

Einstein thereafter illustrated this point with another thought experiment. Imagine that you once again have an observer standing on a railway embankment as a train goes roaring by. But this time, each end of the train is struck by a bolt of lightning just as the train’s midpoint is passing. Because the lightning strikes are the same distance from the viewer, their light reaches his eye at the same time. So he rightly says that they occurred together.

Meanwhile, another onlooker on the train is sitting at its exact midpoint. From her perspective, the light from the two strikes also has to travel equal distances, and she’ll likewise measure the speed of light to be the same in either direction. But because the train is moving, the light coming from the lightning in the back has to travel more to catch up, so it reaches her a many moments later than the light coming from the front. Since the light beams arrived at different times, she can only conclude the strikes weren’t simultaneous — that the one in front actually transpired first.

In short, Einstein realized, simultaneity is what is relative. Once you accept that, all the strange things we now associate with relativity are a matter of simple algebra. Thereby came the simplest looking equation of all time.

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This post was last updated on October 31st, 2021 at 04:18 pm

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