Lets get started
Starting today, I’ll be writing some articles about general science, which I am sure, will spur your interest in the subject. Let me set something straight at the very outset. I am not a scientist in the first place, but I come from a backdrop of science which helps matters. Again the articles are not intended to be taken as reference material for scientific pursuits (okay, that’s exaggeration) but are merely meant for reading pleasure. My motive is to open the reader’s mind to the breathtaking landscape of science. So, fasten your belts and we are set to go.
The first one of the many articles that will follow is about theory of relativity postulated by Albert Einstein and other models stemming from it. We will look at what makes the universe so fascinating and why the theory of relativity has accrued the attention it did. In fact terming the universe as fascinating is an understatement. It is well beyond that. Let’s begin then, folks.
In 1905, Albert Einstein published three papers that established his reputation as one of the greatest brains to have ever blessed the science fraternity. To really appreciate why Einstein’s research was groundbreaking, it is imperative to understand the landscape of science before Einstein arrived.
Before Einstein
In the early 80’s of the nineteenth century, the universe was generally accepted to be made up of a fluid substance, called ether, and light was considered to be waves propagating through it. As an analogy, light waves are to ether what sound is to air. Another, widely accepted school of thought was that the speed of light should inherently differ to an observer depending on the speed and the direction in which he was moving. It is exactly the same as the difference of speed you would feel, contingent on the direction of your travel, relative to another car that is moving. So, by the same token, the speed of light should appear less to you if you are moving in its direction, and the speed should appear more if your direction of travel is against its direction. However experiments carried out by researchers in Cleveland, Ohio, suggested that the speed of light is the same irrespective of the motion or the direction of the observer.
Timelessness
Enter Einstein. Taking cue from the above fact, Einstein dismissed the idea of ether as redundant. He is even believed to have termed the ether theory as bogus. He believed that all physical phenomena should be governed by laws that are uniform and constant, regardless of whether the person was moving or stationary. This was one blow to classical physics. But the final nail on the coffin proved to be his idea that time is not a universal absolute as it was widely conceived to be, but relative.
Though the idea seems counter-intuitive at first blush, there are ample proofs that suggest the veracity of the concept. The first among them is when two clocks are brought together and synchronized, and then one is moved away and brought back, the clock which has undergone the traveling would be found to be lagging behind the clock which has stayed put. This clearly shows that time is relative. Another extension of this concept is the twin paradox which is explained below.
The Twin Paradox
Imagine there are two folks who are identical to each other in all respects. One of them (say, Harry) embarks on a space-craft and blasts away into space at a speed proportionate to that of light. The other twin (say, Sally) stays on earth. Our beloved space tourist gets the surprise of his life when he sets his foot on earth after his expedition. Can you guess what? He finds that his sister has grown older than he. Did time stop for him? Or was it the other way round – time passed too quickly for his sister than it did for him? The answer is yes and no, both. Confused? Well, theory of special relativity provides the answer. To pit it in Einstein’s own words,”Time is personal and not universal.”
E=MC²
Let’s now shift focus and explore yet another of Einstein’s invaluable contribution. He came up with the most famous equation known to man, E=MC². This equation gracefully elucidates why it is impossible for a physical body to surpass the speed of light. Einstein proposed that to accelerate, one needs to expend energy. To even equal the speed of light, one would therefore need an infinite expenditure of energy which is inconsistent with the law of conservation of energy.
The Atom Bomb
As it turns out, this equation has been also responsible for bringing untold calamities to mankind. Atom Bombs! At the core of the most destructive of bombs, this equation is at work. To know how a bomb works, read on. An atom is made up of several neutrons and protons with electrons revolving around it. Experiments have shown that the total mass of the nucleus (which is aggregation of protons and neutrons), is less than the sum of the masses of the individual protons and neutrons that go into making it. Where is the missing mass? Again, E=MC² explains it. The mass that apparently seems to disappear is indeed converted into energy. If you could by any way, give vent to that energy, you have the ultimate disaster recipe in place for you, ready to be served. This is how atom bombs found their way into history.
It is noteworthy to mention that even though Einstein laid the foundation on which atom bombs could be built, he himself was never a part of the Manhattan project that led to the dropping of the two deadly bombs at Nagasaki and Hiroshima.
Einstein and Gravity
This however did not mean it was plain sailing for Einstein all through. Though his theory of relativity could explain concepts like magnetism and electricity, it was not compatible with Newton’s laws of gravitation. Newtonian theory suggests that if there is any change in the distribution of matter of the universe at some point in the space, the change must innately be felt elsewhere instantaneously, which in a way meant that it is possible for the change to propagate at the speed of light. That is what the word instantaneously is suggestive of. But Einstein had long dismissed the absoluteness of time. So he refused to buy Newton’s theory. He was aware that there was a missing link and he set out to find it.
Newtonian theory suggests that an apple falls to the ground because the earth exerts a pull on it, which we all know to be the gravitational pull. In scientific literature, the apple crashing down on Newton’s head is the same as Newton accelerating upwards to hit the stationary apple. This theory works fine if we consider the world as flat, but how does one explain the spherical shape of the earth. In a spherical earth, Einstein suggested that people living at opposite ends of the earth must continue to accelerate outward, with the distance between them remaining the same. It was this anomaly that convinced Einstein to come to yet another groundbreaking conclusion – a physical body warps space-time and it is this curvature that went on to explain so many phenomena that had remained unexplained so far, like explaining gravity in the pretext of a spherical earth.
Space-time
Einstein was convinced that space-time is curved and not flat as it was assumed to be hitherto. What this meant in layman terms was that gravity is just an expression of the fact that space time is curved. Very simply stated this means that the apple inherently tries to move in a straight line, but because a massive body as the earth warps space-time, it appears to fall into the earth. This new theory was called the general theory of relativity to distinguish it from the original theory without gravity, which is now known as the special theory of relativity. Extending the same concept to the universe we get another interesting observation. Since the universe is full of matter, it follows that all bodies should continue to fall through the space-time continuum. This implies the universe is either expanding or contracting and as observations have shown the universe is indeed expanding with every passing day.
The Universe through Einstein’s eyes
As it turns out astronomical data collected from various sources showed that galaxies are moving away from each other and their speed is in direct proportion to the distance between them. So, it is reasonably easy to conclude that at one point of time they must have been close together. This was one major reason that led scientists to adopt the big-bang theory to explain the origin of the universe. Again there were issues that were not resolved. Big bang suggested that time must have a beginning - an idea Einstein had dismissed at the very outset. Further the theory predicted that as a star continued to burn its nuclear fuel, eventually a time would come when the star would exhaust the fuel and the warping of space-time would become so severe (read extremely large gravity) that not even light would escape from it. This state is more commonly referred to as the black hole. To put it in Einstein's linguistics, time would come to an end, which is again a contradiction to what he proposed. Thus, theory of relativity failed at the beginning and at the end of a star's lifecycle. Later scientists discovered that this was not exactly a fallacy but just a gap that arose because quantum mechanics was not taken into account. With quantum theory considered, all the pieces of the puzzle fit together.
Finally
Exhilarating, isn't it? When World War 2 finally came to an end he was offered to take over the newly created state of Israel, which he ardently refused saying this, which still lingers on, 'Politics is for the moment, but an equation is for eternity.' How true. E=MC² is still his best epitaph and memorial. It should last till the end of time.
Starting today, I’ll be writing some articles about general science, which I am sure, will spur your interest in the subject. Let me set something straight at the very outset. I am not a scientist in the first place, but I come from a backdrop of science which helps matters. Again the articles are not intended to be taken as reference material for scientific pursuits (okay, that’s exaggeration) but are merely meant for reading pleasure. My motive is to open the reader’s mind to the breathtaking landscape of science. So, fasten your belts and we are set to go.
The first one of the many articles that will follow is about theory of relativity postulated by Albert Einstein and other models stemming from it. We will look at what makes the universe so fascinating and why the theory of relativity has accrued the attention it did. In fact terming the universe as fascinating is an understatement. It is well beyond that. Let’s begin then, folks.
In 1905, Albert Einstein published three papers that established his reputation as one of the greatest brains to have ever blessed the science fraternity. To really appreciate why Einstein’s research was groundbreaking, it is imperative to understand the landscape of science before Einstein arrived.
Before Einstein
In the early 80’s of the nineteenth century, the universe was generally accepted to be made up of a fluid substance, called ether, and light was considered to be waves propagating through it. As an analogy, light waves are to ether what sound is to air. Another, widely accepted school of thought was that the speed of light should inherently differ to an observer depending on the speed and the direction in which he was moving. It is exactly the same as the difference of speed you would feel, contingent on the direction of your travel, relative to another car that is moving. So, by the same token, the speed of light should appear less to you if you are moving in its direction, and the speed should appear more if your direction of travel is against its direction. However experiments carried out by researchers in Cleveland, Ohio, suggested that the speed of light is the same irrespective of the motion or the direction of the observer.
Timelessness
Enter Einstein. Taking cue from the above fact, Einstein dismissed the idea of ether as redundant. He is even believed to have termed the ether theory as bogus. He believed that all physical phenomena should be governed by laws that are uniform and constant, regardless of whether the person was moving or stationary. This was one blow to classical physics. But the final nail on the coffin proved to be his idea that time is not a universal absolute as it was widely conceived to be, but relative.
Though the idea seems counter-intuitive at first blush, there are ample proofs that suggest the veracity of the concept. The first among them is when two clocks are brought together and synchronized, and then one is moved away and brought back, the clock which has undergone the traveling would be found to be lagging behind the clock which has stayed put. This clearly shows that time is relative. Another extension of this concept is the twin paradox which is explained below.
The Twin Paradox
Imagine there are two folks who are identical to each other in all respects. One of them (say, Harry) embarks on a space-craft and blasts away into space at a speed proportionate to that of light. The other twin (say, Sally) stays on earth. Our beloved space tourist gets the surprise of his life when he sets his foot on earth after his expedition. Can you guess what? He finds that his sister has grown older than he. Did time stop for him? Or was it the other way round – time passed too quickly for his sister than it did for him? The answer is yes and no, both. Confused? Well, theory of special relativity provides the answer. To pit it in Einstein’s own words,”Time is personal and not universal.”
E=MC²
Let’s now shift focus and explore yet another of Einstein’s invaluable contribution. He came up with the most famous equation known to man, E=MC². This equation gracefully elucidates why it is impossible for a physical body to surpass the speed of light. Einstein proposed that to accelerate, one needs to expend energy. To even equal the speed of light, one would therefore need an infinite expenditure of energy which is inconsistent with the law of conservation of energy.
The Atom Bomb
As it turns out, this equation has been also responsible for bringing untold calamities to mankind. Atom Bombs! At the core of the most destructive of bombs, this equation is at work. To know how a bomb works, read on. An atom is made up of several neutrons and protons with electrons revolving around it. Experiments have shown that the total mass of the nucleus (which is aggregation of protons and neutrons), is less than the sum of the masses of the individual protons and neutrons that go into making it. Where is the missing mass? Again, E=MC² explains it. The mass that apparently seems to disappear is indeed converted into energy. If you could by any way, give vent to that energy, you have the ultimate disaster recipe in place for you, ready to be served. This is how atom bombs found their way into history.
It is noteworthy to mention that even though Einstein laid the foundation on which atom bombs could be built, he himself was never a part of the Manhattan project that led to the dropping of the two deadly bombs at Nagasaki and Hiroshima.
Einstein and Gravity
This however did not mean it was plain sailing for Einstein all through. Though his theory of relativity could explain concepts like magnetism and electricity, it was not compatible with Newton’s laws of gravitation. Newtonian theory suggests that if there is any change in the distribution of matter of the universe at some point in the space, the change must innately be felt elsewhere instantaneously, which in a way meant that it is possible for the change to propagate at the speed of light. That is what the word instantaneously is suggestive of. But Einstein had long dismissed the absoluteness of time. So he refused to buy Newton’s theory. He was aware that there was a missing link and he set out to find it.
Newtonian theory suggests that an apple falls to the ground because the earth exerts a pull on it, which we all know to be the gravitational pull. In scientific literature, the apple crashing down on Newton’s head is the same as Newton accelerating upwards to hit the stationary apple. This theory works fine if we consider the world as flat, but how does one explain the spherical shape of the earth. In a spherical earth, Einstein suggested that people living at opposite ends of the earth must continue to accelerate outward, with the distance between them remaining the same. It was this anomaly that convinced Einstein to come to yet another groundbreaking conclusion – a physical body warps space-time and it is this curvature that went on to explain so many phenomena that had remained unexplained so far, like explaining gravity in the pretext of a spherical earth.
Space-time
Einstein was convinced that space-time is curved and not flat as it was assumed to be hitherto. What this meant in layman terms was that gravity is just an expression of the fact that space time is curved. Very simply stated this means that the apple inherently tries to move in a straight line, but because a massive body as the earth warps space-time, it appears to fall into the earth. This new theory was called the general theory of relativity to distinguish it from the original theory without gravity, which is now known as the special theory of relativity. Extending the same concept to the universe we get another interesting observation. Since the universe is full of matter, it follows that all bodies should continue to fall through the space-time continuum. This implies the universe is either expanding or contracting and as observations have shown the universe is indeed expanding with every passing day.
The Universe through Einstein’s eyes
As it turns out astronomical data collected from various sources showed that galaxies are moving away from each other and their speed is in direct proportion to the distance between them. So, it is reasonably easy to conclude that at one point of time they must have been close together. This was one major reason that led scientists to adopt the big-bang theory to explain the origin of the universe. Again there were issues that were not resolved. Big bang suggested that time must have a beginning - an idea Einstein had dismissed at the very outset. Further the theory predicted that as a star continued to burn its nuclear fuel, eventually a time would come when the star would exhaust the fuel and the warping of space-time would become so severe (read extremely large gravity) that not even light would escape from it. This state is more commonly referred to as the black hole. To put it in Einstein's linguistics, time would come to an end, which is again a contradiction to what he proposed. Thus, theory of relativity failed at the beginning and at the end of a star's lifecycle. Later scientists discovered that this was not exactly a fallacy but just a gap that arose because quantum mechanics was not taken into account. With quantum theory considered, all the pieces of the puzzle fit together.
Finally
Exhilarating, isn't it? When World War 2 finally came to an end he was offered to take over the newly created state of Israel, which he ardently refused saying this, which still lingers on, 'Politics is for the moment, but an equation is for eternity.' How true. E=MC² is still his best epitaph and memorial. It should last till the end of time.
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