EINSTEIN and The Theory of Relativity

It has been 64 years since Einstein departed from this world but it hasn’t stopped him from making his way into our news sections every now and then. It only seems as if every step in the advancement of technology only but reaffirms his place as the big bad of the Physics world. We are still discovering new items and phenomenon in the universe even over a hundred years since he theorized them, some of which even he believed we might not ever be able to find.

His Life

He was born in Germany on March 14, 1879 in the city of Ulm in the state of Württemberg to a Jewish middle-class family. They moved to Munich very shortly after his birth and then, owing to business difficulties a few years later, they moved to Italy. He moved to Switzerland for his secondary education in 1895 and renounced his German citizenship in 1933 after moving to the United States in 1930. He married the love of his life, Mileva Maric, in 1903 and had 3 children, Lieserl, Hans and Eduard. The couple’s marriage lasted for 16 years before he married his first cousin, Elsa Lowenthal who died in 1936. He remained true to only science for the rest of his life.

General Relativity

Newton believed that gravity was a force and that anything with mass pulled everything else towards it with a force. He had established a concept of a frame of reference respective to which everything else accelerated. The Earth was one, so was space and so was the Sun from the right perspective. Einstein was not entirely satisfied with it.

· Earth Accelerating up?

While Newton believed that any number of objects, falling towards a gravitational field were the object accelerating. Einstein argued that if a body inside a box was in free fall, it would experience no forces on it. It would be indistinguishable from a body in space. Hence, by Newton’s logic, the Earth is actually the object that accelerates up! This is only true however if the Earth exists in a curved, non-flat, space-time. In that, a lot of very weird things happen. All this led to Einstein formulating the theory of General relativity that makes all the predictions that we have confirmed to be true so far.

This theory of gravitation took Einstein 8 years to complete. Once he did in 1915, many other hurdles lied ahead. It took him countless struggles and another 4 years before people would start to take this theory seriously and he had almost given up before that. This theory had predicted that gravity bends light which was finally possible to put this theory to the test during the solar eclipse of 1919 where the light of mercury was observed, from behind the sun, at exactly the angle at which Einstein’s theory had predicted. He would go on to become a superstar from that point on.

Speed of Light

The speed of light in mph is about 621 million which translates to about a billion km/h. The interesting this is that this speed remains the same in a medium no matter how fast or slow you are moving. It is intuitive that if you are moving at a certain speed and you throw a ball at some speed, the speed of the ball will be the sum of the speed at which you throw the ball and your speed when you threw it. This is not the case with light. It always travels at about 300,000km (186,000 miles) every second in a vacuum, and counter to what relativity implies, every single observer agrees upon its speed. But why does the universe care so much about it? Why must there be a speed limit to the universe?

· The Reality of the Situation

In reality, it doesn’t. The speed of light is basically just the fastest time in which two points in the universe can interact. If the speed were infinite (as implied by Newton’s mechanics and Galilean Relativity) then all matter in the universe, space and time would cease to exist. Think about it, imagine light travelling infinitely fast and even the things that travel with the speed of light, nothing would exist. Everything would pass by in a moment. It would also take infinite energy to make any matter as evidenced by his equation E=mc².

In discovering that there was a major flaw in Newtonian mechanics, Einstein predicted the speed of causality – the causal speed limit – which was equivalent to the speed of light. For the laws of electricity and magnetism, as we know them, to work, (which they do) we need a maximum value of causality. It the maximum speed at which two parts of the universe can talk to or interact with each other.

EMC2

Said to be the most famous equation in the world, he revolutionized the world with this simple formula in 1905 at the mere age of 26. No, the cryptocurrency EMC2 – Poloniex – was not coined by him (although it was inspired by and a tribute to him).  It implies that mass and energy are interchangeable. Contrary to what it later became famous as, Einstein wrote his equation initially as M= E/C² and not E=MC². And that was for a very valid reason.  It actually implied that the more energy you have in a body, the more it’s total mass. This means that at extremely high speeds, the mass should increase so much that it actually slows the body down more and more. This is also the reason why only massless particles can travel at the speed of light. Mass resists motion.

This equation also implies that because of the extremely high value of c, with the right method, theoretically, you could extract a huge amount of energy from very small mass objects. How much energy? Anything with mass equivalent to the mass of a cat could power an entire average sized country for a whole year. So why do we have to burn so much? Because burning and exploding are extremely inefficient ways of extracting energy. With the ways we use currently, you mostly just transfer the mass into other forms which releases very low energy. More efficient ways to extract energy, though, do not exist so far, not even in theory.

Special Relativity

His work and study on the electrodynamics of moving bodies had led him to a golden point in his career in 1905 when he published his paper on the description of the physical phenomena as described by the observers. The two main postulates of the theory are:

1. Physics works the same everywhere, regardless of the inertial frame of reference.
2. The cosmic speed limit in a vacuum is the same for all observers regardless of their velocity.

These laws have very interesting implications. They imply that time and space work differently for different observers, meaning that people moving at a speed will observe time and space differently from people at rest. This is because space and time bend individually to keep ‘space-time’ constant.

Relativistic Effects

·        Time Dilation

Imagine the world from the perspective of the massless photon of light. How does time move for it? Special relativity predicts that time appears frozen for an object travelling at the speed on light. The theory implies that the faster an object moves; the slower time runs for the object. Meaning that the faster you move through space, the slower you move through time. This means that theoretically, if you were moving at a very high speed, you would age more slowly than the people not moving at all.

·        Length Contraction

Since the relative velocity between two observers, one at rest and the other at motion is the same, objects moving at extremely high speeds must observe shorter lengths in space because of the shorter amount of time they observe. This is evidenced by special relativity which states that distances shorten for objects moving close to the speed of light.

·        Mass Variation

The mass of an object, according to Einstein, increases at extremely high speeds. The total mass of a body is the sum of its rest mass and relativistic mass. The relativistic mass of an object increases with increase in velocity.

This also implies that objects with any mass can not reach the speed of light, the reason being that when the velocity approaches the speed of light, the mass approaches infinity. To accelerate that body further, you would have to provide it infinite energy.

Latest, Greatest Discoveries and Predictions

Over 100 years after his predictions, we are still proving his greatness and cementing his legacy further in the books of history. From gravitational waves to black holes, everything he predicted is giving more reasons to scientists to delve into his predictions from his papers and try to find new worlds of realities for us to uncover.

·        Black Holes

Singularities in the fabric of space-time, black holes are points, in space-time, of infinite density and such high gravity that not even light can escape its clutches. Moreover, they are surrounded by surfaces called event horizons beyond which anything that enters is lost forever. Well almost, every now and then they spew up jets of radiation at nearly the speed of light and over time, they evaporate in a sense. They give off ‘hawking radiation’ really, really, slowly and eventually evaporate away into nothing.

·        Gravitational Waves

Gravitational waves are ripples in the fabric of space-time. Just like ripples in a pond, gravitational waves are oscillations caused by highly massive movement in the fabric of space-time that travel at the speed of light. We discovered them by using the Laser Interferometer Gravitational-waves observatory (LIGO). Using two extremely distant lasers at 90 degrees to each other, they shoot lasers at mirrors which bounce them back and observe any lag in the time t takes the laser beams to return. If they lag for just the right time, then we know that a gravitational wave has just passed by.

·        Worm Holes

We know that there is a maximum speed at which we can travel around the universe and consequently a minimum time. This implies that no matter how quick we travel, there may be points in the universe where we can’t even see let alone reach but there may be a way around this. After his theory of general relativity was published, it was noticed that the black holes may have a counterpart, dubbed as White Holes, which throw out matter infinitely.

In 1935, Einstein and Nathan Rosen wrote a paper on these tunnels through space. They can be imagined from a flat sheet. Imagine folding that sheet of paper in half and ripping a hole with a pencil that penetrates two sides of the paper. Wormholes are just like that. Cosmic shortcuts, wormholes or Einstein-Rosen Bridges are passages that connect different points in space through a passage that is threaded by electrical lines.

Einstein’s Biggest Mistake

The Einstein’s field equations are equations that relate the curvature of space-time to the amount of matter and energy in the universe. When Einstein was applying his field equations to the universe, he added a constant in the equations because he thought that the universe should not be static. He removed the constant shortly after because it was believed then that the universe was dull and static.

In 1929, Edwin Hubble looked up from the biggest telescope in the world and discovered not only that there were billions and billions of galaxies in the universe, but also that these galaxies were moving away from each other. He discovered that the universe wasn’t static after all. When Einstein came to know of this, he added the constant back into the equation. Had he not removed it before, he would’ve intuitively predicted the stretching of the universe 12 years before it had been observed, implying a beginning and an age to the universe. He admitted to it being his biggest blunder. It’s hard to wrap your head around the fact that this man was so smart that his biggest mistake was thinking that he had made a mistake.

Quantum Mechanics

While ‘genius’ may be an insult to describe what he was in the world of the unimaginably big, he wasn’t so about the world of the really small. He didn’t add to Physics are 1925, mainly because he looked to overhaul the quickly escalating theory of the quantum world which he was unable to do. Maybe realizing that he should listen to only himself, held him back from expanding a field which till this day requires a mind as big as him to disentangle.

The problem intuitively lied in his deterministic view of the world. He believed that everything in the universe was set in a way that be easily unfolded hence, the probabilistic nature of quantum mechanics really bothered him. So much so that he would often site to his fellow Niels Bohr, “God doesn’t just throw dice with the universe” to which, Niels Bohr would reply, “Stop telling God what to do!” This debate would go on with Einstein throughout his life. He believed that there must be some hidden variables in the theories of quantum mechanics that determine the outcome. If he was right, it would be his only belief that break physics as we know it and there hasn’t been anything on those variables found so far.

Einstein Quotes and Facts

• The brilliant man that he was, he insisted upon the importance of creativity and imagination.

“Any man who reads too much and uses his own brain too little falls into lazy habits of thinking”

• Einstein’s brain is located at the Princeton University Medical Centre.
• He was a brilliant musician and played the violin while his mother played the piano.

“Be creative, but make sure that what you create is not a curse for mankind”

• No one knew what his IQ actually was but we know that it was really, really, high.
• He won the Nobel prize in Physics in 1921 but neither for general nor special relativity.
• He was against the war and left Germany forever because of Adolf Hitler.

“It has become appallingly obvious that our technology has exceeded our humanity”

• 1905 is known as his Miracle Year. It was the year in which he received his doctorate and had gotten 4 of his papers published.

“I see a clock, but I cannot envision the clockmaker. The human mind is unable to conceive of the four dimensions, so how can it conceive of a God, before whom a thousand years and a thousand dimensions are as one?”

• He loved sailing.
• Contrary to popular belief, he did not fail in school. He did however fail in an entrance exam to university.
• He was offered the presidency of Israel but turned it down.
• His theory of relativity has stood its ground in front of every test we’ve thrown at it so far.

“Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.”