Comprehension
In 2024, we are celebrating the 50th anniversary of Hawking's groundbreaking formula, a landmark in scientific theory that uncovers the remarkable nature of black holes. When Hawking passed away in March 2018 at the age of 76, his wish was honored, and the formula was inscribed on his tombstone in Westminster Abbey. He donated his office and personal belongings to the nation instead of paying inheritance tax. While sorting through Hawking's possessions, my colleagues at the Science Museum in London discovered the profound impact of the formula, which appeared in his papers, written bets, keepsakes, and even a silver beaker presented to him by the producers of the 2015 Hollywood movie "The Theory of Everything."
The idea behind black holes, which are the focus of this notable equation, was contemplated by theorists long before any tangible proof was found. In 1783, John Michell, a parson in Thornhill near Leeds, speculated about 'dark' stars using Sir Isaac Newton's principles. Newton regarded gravity as a force and light as particle-based. Michell suggested that light particles from a star would slow down due to the star's gravity, akin to how a bullet decelerates when fired into the sky from Earth. If the star’s gravity was intense enough, it would pull the light back to the surface. Although Michell's concept hinted at black holes, he was incorrect in crucial aspects. Albert Einstein’s 1915 theory of general relativity, which posits that the speed of light is constant, redefined gravity not as a force but as a distortion of spacetime, combining space and time. Earth, for example, bends the Universe in this manner, causing satellites to orbit along these curves, which we interpret as gravity.
Soon after Einstein released his theory, Karl Schwarzschild, a German artillery officer and physicist, used Einstein’s equations to propose that a mass could warp spacetime so severely that it would become invisible. However, his conclusions did not gain much recognition. In 1939, American theoretical physicist J. Robert Oppenheimer, who would later become famous for his role in developing the atomic bomb, alongside Hartland Snyder, showed how a spherical dust cloud could collapse into a region from which light could not escape. Their work did not immediately persuade their contemporaries, though astronomers eventually found evidence of extremely dense objects.
The idea behind black holes, which are the focus of this notable equation, was contemplated by theorists long before any tangible proof was found. In 1783, John Michell, a parson in Thornhill near Leeds, speculated about 'dark' stars using Sir Isaac Newton's principles. Newton regarded gravity as a force and light as particle-based. Michell suggested that light particles from a star would slow down due to the star's gravity, akin to how a bullet decelerates when fired into the sky from Earth. If the star’s gravity was intense enough, it would pull the light back to the surface. Although Michell's concept hinted at black holes, he was incorrect in crucial aspects. Albert Einstein’s 1915 theory of general relativity, which posits that the speed of light is constant, redefined gravity not as a force but as a distortion of spacetime, combining space and time. Earth, for example, bends the Universe in this manner, causing satellites to orbit along these curves, which we interpret as gravity.
Soon after Einstein released his theory, Karl Schwarzschild, a German artillery officer and physicist, used Einstein’s equations to propose that a mass could warp spacetime so severely that it would become invisible. However, his conclusions did not gain much recognition. In 1939, American theoretical physicist J. Robert Oppenheimer, who would later become famous for his role in developing the atomic bomb, alongside Hartland Snyder, showed how a spherical dust cloud could collapse into a region from which light could not escape. Their work did not immediately persuade their contemporaries, though astronomers eventually found evidence of extremely dense objects.
Question: 1
Which of the following statements best explains the evolution of the understanding of gravity from Michell’s concept to Einstein’s theory and its implications?
Which of the following statements best explains the evolution of the understanding of gravity from Michell’s concept to Einstein’s theory and its implications?
Updated On: Aug 20, 2024
- Michell’s 'dark stars' were based on Newton’s ideas, viewing gravity as a force that could pull light back to a star’s surface. At the same time, Einstein’s general relativity described gravity as a warping of spacetime, leading to a deeper understanding of black holes.
- Michell’s 'dark stars' theory assumed that light could escape from extremely dense stars, but Einstein’s theory showed that gravity could bend light, later confirmed by Karl Schwarzschild’s equations.
- Michell’s concept of 'dark stars' was proven entirely correct by Einstein’s theory, which also described gravity as a force but added that the speed of light depends on the gravitational field.
- Michell’s idea of 'dark stars' was based on an incorrect understanding of light and gravity, which Einstein corrected by introducing the idea of spacetime curvature. However, this theory had no significant impact on modern astrophysics.
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The Correct Option is A
Solution and Explanation
The Correct Option is (A):Michell’s 'dark stars' were based on Newton’s ideas, viewing gravity as a force that could pull light back to a star’s surface. At the same time, Einstein’s general relativity described gravity as a warping of spacetime, leading to a deeper understanding of black holes.
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Question: 2
Based on information in the passage, each of the following statements is a plausible explanation for why Michell's ideas did not immediately lead to the modern concept of black holes except:
Based on information in the passage, each of the following statements is a plausible explanation for why Michell's ideas did not immediately lead to the modern concept of black holes except:
Updated On: Aug 20, 2024
- Michell's concept was based on Newtonian mechanics, which viewed light as particles.
- General relativity was not yet formulated during Michell's time.
- Michell correctly predicted the constant speed of light in a gravitational field.
- Michell's concept did not account for the warping of spacetime as described by Einstein.
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The Correct Option is C
Solution and Explanation
The Correct Option is (C):Michell correctly predicted the constant speed of light in a gravitational field.
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Question: 3
Assume that one of the following actions is taken by the scientific community. Which of these actions would probably give the author of this passage the greatest support?
Assume that one of the following actions is taken by the scientific community. Which of these actions would probably give the author of this passage the greatest support?
Updated On: Aug 20, 2024
- Efforts to further investigate the implications of general relativity on black holes.
- Efforts to disprove Einstein’s theory of general relativity.
- Efforts to revive Newtonian mechanics as the primary theory of gravity.
- Efforts to diminish the importance of Hawking's contributions to black hole theory.
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The Correct Option is A
Solution and Explanation
The Correct Option is (A):Efforts to further investigate the implications of general relativity on black holes.
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Question: 4
Which of the following best analyzes the implications of Schwarzschild's work on Einstein’s equations and the initial reaction of the scientific community?
Which of the following best analyzes the implications of Schwarzschild's work on Einstein’s equations and the initial reaction of the scientific community?
Updated On: Aug 20, 2024
- Schwarzschild’s work laid the groundwork for the modern understanding of black holes, despite initial skepticism.
- Schwarzschild’s conclusions were widely accepted immediately by the scientific community.
- Schwarzschild’s work was dismissed because it was purely hypothetical and lacked empirical evidence.
- Schwarzschild’s conclusions contradicted Einstein’s theories and were thus rejected.
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The Correct Option is A
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The Correct Option is (A):Schwarzschild’s work laid the groundwork for the modern understanding of black holes, despite initial skepticism.
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Top Questions on Reading Comprehension
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THE FAIR ISLE METHOD: Fair Isle knitting is a traditional technique that involves using two or more colours of yarn in a single row to create intricate patterns and designs. This method requires careful tension management to ensure even stitches and prevent puckering. To begin, select your colours and cast on the desired number of stitches. As you knit, alternate between colours every few stitches, carrying the unused yarn along the back of the work. Mastering the Fair Isle technique allows you to create stunning visual effects in garments, accessories, and home textiles.
THE CONTINENTAL STYLE: The Continental knitting style, often referred to as “picking,” involves holding the yarn in the left hand while the right hand manipulates the needles. This method allows for greater speed and efficiency, particularly when working with complex patterns or multiple colours. To practice this style, start by casting on your stitches and using your left hand to tension the yarn. With each stitch, simply “pick” the yarn with your right needle, forming a quick and fluid motion. As you become comfortable with this technique, you may find that your overall knitting speed and comfort improve significantly.
THE SHORT-ROW TECHNIQUE: Short-row knitting is an advanced technique that allows for the creation of shaped garments, such as sleeves and shoulders, without the need for complex shaping. To make a sleeve using this technique, begin by casting on the required number of stitches. Work a portion of the row, then turn your work and return without completing the full row to create the “short rows” that shape the curves of the sleeve. To prevent holes at the turn, wrap the stitch before you turn your work. Repeat this process as needed to achieve the desired shaping and dimension of the sleeve. Once you have shaped the sleeve, you can then sew the side seams to connect the pieces of your garment and finally, complete the edges to ensure a clean finish. This method not only helps shape curves but also adds dimension to your piece, allowing you to enhance fit and style.- AILET BALLB (Hons.) - 2025
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The Story of Coffee
Coffee, a beloved beverage enjoyed by millions around the globe, has a rich and captivating history that spans centuries. The story of coffee begins in the ancient highlands of Ethiopia, where, according to legend, a goat herder named Kaldi discovered the stimulating effects of coffee beans. One day, Kaldi noticed his goats frolicking with unusual energy after eating red berries from a certain tree. Curious, he tried the berries himself and experienced a newfound alertness. This discovery soon spread to monasteries, where monks used it to stay awake during long hours of prayer. From Ethiopia, coffee cultivation and consumption spread to the Arabian Peninsula, particularly in Yemen, where the practice of roasting coffee beans and brewing the drink began to take shape. By the 15th century, coffee had become a popular beverage in the Islamic world, with coffee houses known as ‘qahveh khaneh’ emerging as social hubs for conversation, music, and intellectual exchange. These coffee houses became centers of culture and commerce, influencing the spread of coffee to Turkey and beyond, eventually reaching Europe. In Europe, coffee initially faced resistance from religious authorities who considered it a ‘Muslim drink’ and tried to ban it. However, its popularity persisted, and by the 17th century, coffee houses had sprung up in major European cities, becoming important gathering places for artists, writers, and thinkers. The stimulating effects of coffee were embraced during the Age of Enlightenment, where it was seen as a catalyst for intellectual discussion and innovation. The journey of coffee continued with the establishment of colonial plantations in tropical regions such as the Caribbean, Central and South America, and Southeast Asia. These plantations fuelled the global demand for coffee, transforming it from a regional specialty to a major commodity. The industrial revolution further accelerated coffee production and consumption, leading to innovations in coffee brewing methods and the development of instant coffee. In the modern era, coffee has evolved into a deeply ingrained part of daily life for people worldwide. Its cultural significance spans from the bustling cafes of Paris to the quiet coffee farms of Colombia. Today, coffee remains not only a popular beverage but also a symbol of social interaction, productivity, and enjoyment. Whether sipped slowly over a conversation with friends or grabbed hastily on the way to work, the story of coffee continues to unfold, intertwining with the histories and cultures of countless societies across the globe.- AILET BALLB (Hons.) - 2025
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The intricate world of modern manufacturing is a web of precision and innovation, where even the tiniest components play a pivotal role. One such element, often overlooked but crucial, is the sub-subpart. Whether it’s a carpenter fashioning a bespoke piece of furniture or an automobile engineer designing the next generation of vehicles, the creation of sub-subparts is a fundamental process that demands meticulous craftsmanship and cutting-edge technology. In the realm of woodworking, carpenters frequently work with sub-subparts like dowels, screws, and hinges. These minute components may appear insignificant, yet they determine the structural integrity and functionality of the final product. Crafting a dowel, for instance, begins with selecting the appropriate wood species, followed by precision cutting and shaping. The result is a perfectly cylindrical, sturdy sub-subpart that seamlessly joins two larger pieces of wood. The advent of computer-aided design (CAD) and computer numerical control (CNC) machines has revolutionised this process, enabling carpenters to create sub-subparts with unparalleled precision.
Similarly, in the automobile industry, sub-subparts are the unsung heroes of vehicle construction. Take, for instance, the ball bearing—a minuscule but essential component in the wheels and transmission system. Manufacturing these precision-engineered spheres involves intricate processes like forging, heat treatment, and precision machining. Modern techniques such as laser cutting and 3D printing have streamlined production, ensuring that these sub-subparts meet the demanding standards of the automotive sector. The manufacturing of sub-subparts is a testament to the convergence of traditional craftsmanship and cutting-edge technology. Whether it’s a carpenter’s workshop or a high-tech automotive assembly line, the quest for perfection in sub-subpart creation remains unwavering. The attention to detail and precision required in these processes is a testament to the dedication of craftsmen and engineers alike.
To conclude, while sub-subparts may be small in size, their significance in various industries cannot be overstated. Whether it’s a carpenter working on a timeless piece of furniture or an automotive engineer striving for superior performance, the manufacturing of sub-subparts is a crucial step towards achieving excellence in craftsmanship and technology. This fusion of tradition and innovation accentuates the essence of modern manufacturing.- AILET BALLB (Hons.) - 2025
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