How Einstein Thought of the Theory of Relativity

In 1895, a 16-year-old boy imagined himself chasing a beam of light. This thought eventually changed the world forever. So how could one thought change the world so thoroughly?

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Script:
We cannot start talking about Einstein without discussing a classical physicist Sir Isaac Newton. In 1687, Newton published his book “Mathematical Principles of Natural Philosophy”. In the book, he described his three Laws of Motion and the Law of Gravity. His book is considered one of the most important writings in the history of mankind. After watching an apple fall, he asked himself a question. And if the apple falls, does the moon also fall? These questions led him to discover the Law of Gravity.

According to his Law of Gravitation, every object in the universe enacts its own force of attraction on another object. And this force is the reason why we are stuck on Earth, why the moon orbits the Earth, and indeed, why the universe exists. But that didn’t answer all of Newton’s questions. Like, why do objects attract each other? What is the source of gravity? And why does Mercury's orbit jiggle?

The rest remained a mystery until the era of Albert Einstein. In 1915, #Einstein published his Theory of General #Relativity, or in other words, his theory of #Gravity. In this theory, Einstein explained gravity and its source. He answered all the questions that Newton couldn’t, like Mercury’s precession.

Let’s take a step back here to 1905, to truly grasp where these different pieces of the puzzle come to life. This year, Einstein published his Theory of Special Relativity. It deals with the speed of light and the motion of objects. It was fine with non-accelerating objects, but the theory did not apply when gravity was present, or if the object was accelerating. He couldn’t quite figure the rest out. Until one fine day in 1907. He was observing a window washer on a ladder and had an epiphany.

He thought about what he would be experiencing while falling. He imagined himself there and realized that while falling, the ground would not be pushing him, so he would be in a free fall. That put some of the pieces together, but he still wasn’t fully finished. He began to think about falling again, this time he imagined himself in a room with no windows. On the surface of the Earth, you would weigh whatever your weight is now. But imagine if the room was in a spacecraft, moving in an upward direction with the same 9.8 meters per second squared as here on the ground. In that moment, if you were to weigh yourself, you would weigh the same as you do on Earth. Einstein realized that the observer would not be able to tell if he is on a spaceship, or on the surface of the Earth. That is because he would be moving at the exact same rate of acceleration. There would be no way to tell the difference.

This phenomenon is called the Equivalence Principle, which states that an object that is accelerating free of any gravitational pull is essentially no different than the same object that is stationary but affected by gravity. In other words, something moving in space with no gravity has the same mass as something on earth that is not moving. In his special theory of relativity, he could only deal with non-accelerating objects and the speed of light.

Let’s pause here for a second. This means that at that point, he knew how to unify his theory of special relativity with gravity. Luckily, he didn’t stop there. He did another thought experiment. This time he imagined what would happen if he pointed a laser beam from one side of the room towards the other. If the room were in a spaceship that was moving upwards with the same acceleration rate as earth, the height of the beam would slightly be lower on the other side of the room. As the floor moved up, it curved the light and caused it to bend down. But, this principle only applied in space. When he thought about the same experiment on earth, the light would appear to be straight. Of course, these two scenarios only happened in his brain. Let’s just take a brief moment to appreciate how brilliant he is to be able to conduct that experiment, all of that, in his brain.

Einstein wasn’t convinced though, as this violated the principle of equivalence. The acceleration of the room on the spaceship was the same as under the influence of gravity. The heights should be the same in both cases, so why were they different? He realized that the only possibility could be that the light beam must be bending under the gravitational influence. But how could this be? What does this bending of light mean?

[romuluxb]

We owe everything we have today (thus the easy life compared to 200, 000 years ago) to a few brilliant individuals that greatly advanced human understanding. Thank you Einstein, Newton, James Clarke Maxwell, Marie Curie, Edwing Schroedinger, Tesla, Stephen Hawking and many others for getting us this far in a short time span! And rooting and cheering on the current scientists who are very hard at work to better humanity!

[VivecsTDawg]

Einstein's knowledge was almost a century in the future. Truly amazing how he could understand and think about that. Takes an exceptionally open and creative mind to be able to do that.

[itskee]

It's interesting how Einstein's theories all tie together. More interesting the fact that he was able to come up with his Equivalence Theory before man had even left the atmosphere. It goes without saying, but his intelligence is one in a millennia.

[MadeInSeventyFour]

I have watched so many videos explaining Einstein's Theory of Relativity. I have found your explanation to be the best. Simple and concise. Thank you!

[speededits]

Cool animations! Loving the thug life Einstein 😆

[jerichobeach]

Holy shit 7:25 my eyes finally opened now I understand!

I knew about light bending and I knew that despite the bend the speed is unaffected which is cool but what I JUST learned was from the way you said “time must slow down” then I clued in to gravity’s effect on light, speed, time is all connected! Finally I get it thanks. I watched so many of these and I’m aware of time dialation and all that stuff but I never seen such an easy visual representation.

[javierjoemar-spjj]

the most accurate evidence how gravity works is when the bird flew away from ground to sky....

[SynqLuck]

What’s most impressive about the original ideas and theories of these great thinkers, is that they proved these things without ever even going to space. They understand the rules but never needed to leave the earth to test these theories, which just shows how open minded their ideas were. They found ways to test their hypothesis’s with their feet on the ground. Much respect

[tangodman]

Einstein was a rare breed genius who somehow managed to outperform all the other genius of his time. Even 100 years after his theories, we are still verifying and founding everything correct. He has given so much that, it looks like for the next 100 years we will continue to do so.

[AbrehamArega-zx]

Simple & understandable presentation.Thank you

[BeeyondIdeas]

Hope you guys enjoy this episode. Comment which topic we should cover next in our video. See you guys around!

[irfanlone]

Albert Einstein is the only physicist in the history of Science that can be compared with Isaac Newton~Stephen Hawking!

[ALCLITE]

"If I have seen further than others, it is by standing upon the shoulders of giants" - Sir Isaac Newton.

Just as the giant leaps today we make in science are made possible by Einstein, his leaps were made possible by others, and theirs by others, and so on. We couldn't have made it to where we are without ancient people like Eratosthenes, Gan De, up to Gallileo and Faraday. Hell, without Plato and Socrates, we might not have even had a society that allowed for critical thinking!

[OPropagadordaReal]

“What we mean by relative motion in general is perfectly clear to everyone. If we think of a cart moving along a street, we know that it is possible to speak of the cart at rest and the street in motion, just as it is to speak of the cart in motion and the street at rest. This, however, is a very special part of the ideas involved in the principle of Relativity. ”

“It would be fun if we read this in a comic book journal, but when Professor Einstein says this in a lecture at Princeton University, we're supposed to not laugh, and that's the only difference. It's silly, but I can't dismiss the matter with this observation and therefore I will answer very seriously that it is only possible to speak of the street moving while the cart stands still - and believe - when I walk away from the whole experience of a lifetime and I am no longer able to understand the evidence of my senses; which is madness... Self-deception like this is not reasoning; it is the negation of reason; which is the faculty of drawing correct conclusions from the things observed, judged by the light of experience.


It is unworthy of our intelligence and a waste of our greatest gift; but this introduction serves very well to illustrate the kind of illusion that lies at the root of Relativity. When he suggested that the street might be moving while the wheeled cart was standing still, he was asking us to imagine that, in a similar way, the Earth we are standing on might be moving as the stars pass in the night. stop. It's an Appeal Case, where Einstein appeals on behalf of a Copernican Astronomy condemned against Michelson's judgment - Morley, Nordmeyer, Physics, Fact, Experience, Observation and Reason. ”

- Gregard Hickson, “Kings Dethroned”, p. 65-66.

[vidysaras]

Another knowledge to consume this morning! So cool! 🕵🏻‍♀️👩🏻‍💻❤️

[theexplorer]

I Think Einstein Could Imagine A New Colour

[MaqsoodAlamShafiq]

The best explanation so far on Theory of Relativity in plain English.

[shrinivasapte]

Einstein stole the papers from The Great Indian scientist SATYENDRANATH BOSE & took the credit entirely to himself.(Bose's contribution was acknoledged much later)

[lmenascojr]

How could Einstein have “thought” about pointing a laser beam when lasers were invented after his death?

[williamhatfield]

Einstein was a complete fraud who created a set of insoluble equations but was smart enough never to attempt to solve them.