Einstein's genius
I am currently reading "Einstein: his life and universe," by Walter Isaacson. Everyone agrees that Einstein was a genius. It is not widely realized however that Einstein became famous long after he made the startling insights that revolutionized physics and our view of the world. His three important papers published in 1905 were obscure except to the most expert physicists, his work on Special Relativity published in 1907 was not generally accepted until years later, and his major work on his theory of General Relativity which he postulated in 1912 and first presented/published in 1915 (during WWI) was not accepted until it was confirmed by experiment in 1920. Of course, then he became world famous and won the Nobel Prize in 1922, but not for his work on Relativity but for his earlier work on electrodynamics, including the development of the famous equation e=mc2 that links energy with the speed of light c.
I am not an expert on Einstein's work, but I will try to present here a simplified view of his major insights that make the impact of his work understandable. The first insight he had in his gedanken (thought) experiments came when he was sitting in a cafe in Zurich, where he had been taken as a child from Germany, and where he worked as a patent clerk. This job gave him plenty of time to indulge in such pursuits. As he was sitting there he saw a streetcar come around the corner and he had the insight that if an experiment or an event occured in a moving space such as a streetcar, then it might look different for an observer in the streetcar and an observer (himself) on the street. Of course, this was contrary to classical physics in which it was believed that the result of an experiment would be the same when viewed from anywhere. An example of this phenomenon is the Doppler Effect that was first heard by Mr. Doppler when riding on a train, when he heard that the sound of the whistle of a passing train sounded distinctly different than it normally would. He immediately realized that the relative speed of the two trains modulated the sound of the whistle for the moving observer. Another example is if two men are playing ping-pong on a train that is moving away from the stationary observer, to the two men the ping-pong ball moves back and forth but to the stationary observer the ball always moves away from him. As a result of this insight, Einstein postulated that all three spatial dimensions and time formed a four dimensional continuum, that he called space-time, and that objects moved in space-time with a relative effect that led him to call his theory developed from this insight the Special theory of relativity. Of course, this theory was based on advanced mathematical analysis that in time came to be accepted by other physicists.
Several years later, after he had been invited to join the Berlin Scientific Academy and was sitting in his office in the building, he happened to see some men working on a roof across the courtyard. He imagined what would happen if one of the men fell. He considered the Newtonian concept of gravity, that postulated that the man would fall because of the force of gravity of the earth. But, Einstein considered that if the man was in an elevator and the elevator was falling in free space, then to the man it would not appear that he was falling, and in fact the man would continue in a straight line, but his movement would only be distorted if a massive object were nearby. Einstein postulated that space-time is normally uniform, but becomes distorted or curved by the presence of objects, such as planets or the sun, and this alters their trajectory. So that instead of gravity being an attractive force between objects, gravity is the manifestation of the curvature of space-time. An example would be a large ball on a trampoline, other smaller balls will roll down to the larger one, but there is no gravitational attraction, rather they move thru the curvature caused by the larger ball.
Einstein worked for several years on the equations to describe this pheomenon and only after 5 years of effort did he solve the problem. His prediction for his General theory of relativity was that light would be curved by the curvature of space near massive objects and for several years he encouraged astronomers to observe stars near the sun during an eclipse (when the sun's light would be removed) and to compare their positions when the sun was not near. In this way a distortion of the star's positions were observed and the calculation of the deviation corresponded exactly to his prediction.
Einstein had single-handedly revolutionized our understanding of the world using only his thought processes. In doing so he replaced the classical Newtonian view of the world and made it a much less certain place. During the time of his work there were two world wars. He was a pacifist in WWI and was greatly criticized by his fellow Germans for it, and in WWII he was saved as a Jew from Nazism only by his fame. It is fitting that Einstein's fame has continued to grow and he was named "The Man of the Century" in Time magazine for the year 2000.
I am not an expert on Einstein's work, but I will try to present here a simplified view of his major insights that make the impact of his work understandable. The first insight he had in his gedanken (thought) experiments came when he was sitting in a cafe in Zurich, where he had been taken as a child from Germany, and where he worked as a patent clerk. This job gave him plenty of time to indulge in such pursuits. As he was sitting there he saw a streetcar come around the corner and he had the insight that if an experiment or an event occured in a moving space such as a streetcar, then it might look different for an observer in the streetcar and an observer (himself) on the street. Of course, this was contrary to classical physics in which it was believed that the result of an experiment would be the same when viewed from anywhere. An example of this phenomenon is the Doppler Effect that was first heard by Mr. Doppler when riding on a train, when he heard that the sound of the whistle of a passing train sounded distinctly different than it normally would. He immediately realized that the relative speed of the two trains modulated the sound of the whistle for the moving observer. Another example is if two men are playing ping-pong on a train that is moving away from the stationary observer, to the two men the ping-pong ball moves back and forth but to the stationary observer the ball always moves away from him. As a result of this insight, Einstein postulated that all three spatial dimensions and time formed a four dimensional continuum, that he called space-time, and that objects moved in space-time with a relative effect that led him to call his theory developed from this insight the Special theory of relativity. Of course, this theory was based on advanced mathematical analysis that in time came to be accepted by other physicists.
Several years later, after he had been invited to join the Berlin Scientific Academy and was sitting in his office in the building, he happened to see some men working on a roof across the courtyard. He imagined what would happen if one of the men fell. He considered the Newtonian concept of gravity, that postulated that the man would fall because of the force of gravity of the earth. But, Einstein considered that if the man was in an elevator and the elevator was falling in free space, then to the man it would not appear that he was falling, and in fact the man would continue in a straight line, but his movement would only be distorted if a massive object were nearby. Einstein postulated that space-time is normally uniform, but becomes distorted or curved by the presence of objects, such as planets or the sun, and this alters their trajectory. So that instead of gravity being an attractive force between objects, gravity is the manifestation of the curvature of space-time. An example would be a large ball on a trampoline, other smaller balls will roll down to the larger one, but there is no gravitational attraction, rather they move thru the curvature caused by the larger ball.
Einstein worked for several years on the equations to describe this pheomenon and only after 5 years of effort did he solve the problem. His prediction for his General theory of relativity was that light would be curved by the curvature of space near massive objects and for several years he encouraged astronomers to observe stars near the sun during an eclipse (when the sun's light would be removed) and to compare their positions when the sun was not near. In this way a distortion of the star's positions were observed and the calculation of the deviation corresponded exactly to his prediction.
Einstein had single-handedly revolutionized our understanding of the world using only his thought processes. In doing so he replaced the classical Newtonian view of the world and made it a much less certain place. During the time of his work there were two world wars. He was a pacifist in WWI and was greatly criticized by his fellow Germans for it, and in WWII he was saved as a Jew from Nazism only by his fame. It is fitting that Einstein's fame has continued to grow and he was named "The Man of the Century" in Time magazine for the year 2000.
posted by Jack Cohen at 8:49 AM
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