Friday 21 June 2024

The World of Einstein - Part 3

 



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Einstein wrote about himself, “I do what my inner nature drives me to do. It is somewhat embarrassing for me to have received so much love and praise in one lifetime. Arrows of hatred have also been directed at me, but they did not hit me because hatred is from another world, with which I have no connection. I live in a solitude which is painful in youth, but delicious in the years of maturity.”

What was Einstein's world like? In Bengali, the word 'ভুবন' (world) has many meanings. When we talk about Einstein's world, it encompasses all these meanings in different ways. Einstein's personal world was multidimensional. There was Einstein the child, Einstein the student, Einstein the lover, Einstein the husband, Einstein the father, Einstein the scientist, Einstein the philosopher, Einstein the politician – at times it seems like these were distinct identities.

Furthermore, there is a significant difference between the pre-1987 Einstein and the post-1987 Einstein. Until 1987, biographies of Einstein did not reveal his relationships with many women, his mental turmoil with his wife, his divorce from his first wife Mileva, and other such personal issues. Thanks to the relentless efforts of Einstein's secretary, Helen Dukas, all the negative aspects of Einstein's personal life were kept secret. However, in 1987, when the Einstein archives at Princeton University and the Hebrew University of Israel were opened to the public, many unknown aspects of Einstein's personal life were revealed. Especially after the publication of Roger Highfield and Paul Carter's 'The Private Lives of Albert Einstein' in 1993, the saintly image of Einstein turned into that of a 'devil' in the eyes of many – someone who even raised his hand against his wife!




 On October 31, 1993, the New York Times Magazine depicted Einstein with two horns on his forehead, comparing him to a monster. On the other hand, the renowned Time magazine recognized Einstein as the Person of the Century.





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The scientist Freeman Dyson viewed Einstein's life as follows: "Albert Einstein’s life was full of paradoxes." There are many reasons for this. In personal life, contradictions can arise for various reasons. However, contradictions in science are unacceptable. Let's see how the scientist Einstein was contradictory in his own world—his universe. What was Einstein's universe like?

The concept of Einstein's universe began to emerge with the publication of his Special Theory of Relativity. However, he forced the world to rethink the universe when he started publishing his papers on the General Theory of Relativity. In 1915, three of his papers were published in Berlin: "On the General Theory of Relativity," "Explanation of the Perihelion Motion of Mercury from the General Theory of Relativity," and "The Field Equations of Gravitation."

In 1916, the 49th issue of Annalen der Physik published "The Foundations of the General Theory of Relativity." This paper was the first comprehensive presentation of Einstein's General Theory of Relativity. Following the three successive papers on General Relativity published in 1915, this paper presented the final form of General Relativity. It provided a detailed description of how the gravitational field equations are established in non-Euclidean spacetime through tensor analysis. General Relativity can explain the bending of light rays due to the gravitational field, a phenomenon that Newton's classical theory cannot account for. Herein lies the superiority of General Relativity. The universe, which had been viewed through Newton's classical theory, would now be understood through Einstein's General Relativity.

However, writing scientific papers was not enough. Experimental proof was necessary. To prove it, a large-scale experiment with a substantial budget was needed. It took almost three years to prove Einstein's General Theory of Relativity.

In June 1919, on two dates, Einstein's theory of relativity was proven to be true. Sir Arthur Eddington, the director of the Cambridge Observatory and a renowned theoretical physicist from England, observed the bending of starlight around the Sun's gravitational field during a total solar eclipse. This observation confirmed that the path of light is curved by the gravitational field, as predicted by Einstein's theory. In November of that year, the Royal Society announced the confirmed results of Eddington's expedition, making Einstein instantly world-famous. His theory seemed so counterintuitive to the general public that some began to believe that only Einstein had the ability to see the world differently, to understand much more than ordinary people.

Einstein's General Theory of Relativity introduced a revolutionary concept in cosmology known as 'space-time', where the structure of space and time undergoes changes. This led to a profound understanding of the creation and evolution of the universe. The theory established the foundation of black hole theory. Today, any discussion about the general structure of the universe inevitably includes the concept of black holes, without which the modern understanding of the universe is incomplete. There are many black holes in our galaxy, and even at the centre of most known galaxies, there exist black holes.

The concept of a black hole did not arise suddenly. In 1783, the English astronomer John Michell first proposed the idea of a black hole. Stars orbit around black holes at tremendous speeds due to intense gravitational forces. Freeman Dyson likened this scenario to moths circling a fire. Like moths, stars rotate around black holes, and occasionally, every ten thousand years or so, a star falls into a black hole and dies. Most of the star's energy is emitted from the black hole as a very small part of the X-ray or energetic radiation. These small portions of energy are more powerful than a hundred atomic bombs. Space-time or spacetime inside a black hole. Since there is no separate existence of time there, so time doesn't exist there, the order is always kept out and ready. Einstein's General Theory of Relativity's greatest and most reliable proof is this black hole. Stephen Hawking and Roger Penrose proved through their General Theory of Relativity that space-time becomes uniform inside a black hole.

Now, if someone says that a black hole cannot exist, can we accept that? Certainly not. However, if Einstein himself said that a black hole cannot exist, then? Even if we don't want to believe it, the truth is that Einstein never accepted the concept of a black hole. This was his opposition. In 1939, in the 40th issue of Annals of Mathematics, pages 922-936, Einstein attempted to prove in his article "Stationary Systems with Spherical Symmetry Consisting of Many Gravitating Masses" that black holes cannot exist. He created a mathematical black hole model and showed that such a model is impossible due to the gravitational forces among many masses. Because the particles inside a black hole would have to escape at speeds greater than the speed of light, which is not possible in any case. Therefore, black holes cannot exist. However, the main flaw in Einstein's model was elsewhere. He assumed that the black hole is static - or stationary. But no black hole is static; all are dynamic or in motion. The creation of dynamic black holes is due to the gravitational collapse of massive objects.

Did Einstein not understand this matter, or did he choose not to understand it? If he wanted to understand it, people would not necessarily comprehend it. He did not want to understand it. He believed that black holes could not exist, so he assumed that they would not exist. Even if they did exist, he would not accept it, just as he never accepted quantum mechanics. He never wanted to discuss the subject of black holes either. In 1939, when he published a paper opposing black holes, that same year Robert Oppenheimer and Hartland Snyder explained in detail in a research paper how a collapsing star gradually emits radiation and eventually ends up as a black hole. This research paper used Einstein's General Theory of Relativity for its majority of proof. Einstein did not comment on this matter. Not only that - a few years later, Oppenheimer joined the Institute for Advanced Study at Princeton University, where Einstein was working. They were often seen together. However, they never discussed black holes between themselves. Should we conclude that Einstein anchored himself with his science at times - times when he did not want to transgress it himself?

 

References:

1. Albert Einstein, The Einstein Reader, Citadel Press, New York, 2006

2. Freeman Dyson, in Einstein Hundred years of relativity, ed, Andrew Robinson, ABC Books, Sydney, 2005

3. Stephen Hawking, in Einstein Hundred years of relativity, ed, Andrew Robinson, ABC Books, Sydney, 2005


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