The first hint at the existence of extra dimensions came via Einstein’s theory of general relativity. Almost at a glance, the set of ten general relativity equations indicates an ultimate origin for matter and energy. Even without the detailed calculations, a picture emerges from those equations, a picture of simultaneous expansion and deceleration. Only one phenomenon in physics fits this picture: an explosion. A closer study of these general relativity equations reveals that the entire universe burst forth and is still expanding outward from an infinitely dense state. This creation event, often called the Big Bang, has been confirmed in several ways through the past few decades of research. The most direct evidence comes from measurements of the distances and motions of the galaxies and of the temperature and characteristics of the initial explosion’s radiation residue at varying distances from us. This bursting forth of the cosmos from an infinitely small volume, or essentially an infinitely small volume, implies that the universe has a beginning, a starting point in the finite past. Einstein recognized this implication and dared to say that it affirms the necessity of “a superior reasoning power.” Space-Time Theorem Emerges. Einstein’s conclusion went against the grain of astronomers and physicists trained to presume an infinite universe and an irrelevant, if any, Initiator. The simplicity and obvious nature of his conclusion made it all the more irritating. Several attempts were made to prove that this finite beginning arose from incorrect assumptions about the universe’s homogeneity and symmetry. Critics tried introducing all manner of inhomogeneities, asymmetries, and rotations into Einstein’s theory, but to their amazement, these machinations backfired. They actually slightly shortened the time scale back to the beginning. No matter how astrophysicists manipulated the theory, this stubborn singularity would not go away. It was left to the next generation of astrophysicists to figure out why it would not, could not, go away. Over a four-year period, starting in 1966, George Ellis, Stephen Hawking, and Roger Penrose affirmed that any expanding universe governed by general relativity and which also contains at least some matter and energy must possess a singular origin in the finite past. But they went further. In fact, they carried the solution of Einstein’s equations further than anyone else had. In doing so, they discovered that the operation of general relativity guarantees a singular boundary not just for matter and energy but also for space and time. In other words, if general relativity accurately describes the physics of the universe, both the stuff that makes up the universe and the dimensions in which that stuff exists and operates share a common origin, a finite beginning. We call this finding the space-time theorem of general relativity, and it carries profound philosophical and theological significance. In 1970, however, that crucial if still hung over general relativity. Expansion was no longer in doubt; the existence of matter and energy never had been in doubt. And though the operation of general relativity had been affirmed—to 1 percent precision (two decimal places) —it had not yet been established with adequate certainty to put theoreticians’ doubts to rest. By 1980, the level of certainty had improved to better than a hundredth percent precision (four decimal places)—impressive, and yet still not quite enough to satisfy the most skeptical. But in 1993, the lingering shred of uncertainty finally flew away. The Nobel Prize in physics that year went to Russell Hulse and Joseph Taylor for their study of the binary pulsar PSR 1913+16. This stellar system is unique: two neutron stars (one of which is also a pulsar) orbit closely about one another. Through a twentyyear-long study of this system—in which gravitational forces exceed those seen in our solar system by hundreds of thousands of times—a team lead by Taylor was able to affirm the accuracy of general relativity to better than a trillionth percent precision (that is, to fourteen decimal places). In Penrose’s words, this set of measurements “makes Einstein’s general relativity, in this particular sense, the most accurately tested theory known to science!”
Q. Describe the narrator’s purpose in explaining the super scientific theories and its inconclusiveness. You will be required to write a summary in 100 words; write your points in the form of a connected passage and grid format.
Answers
Explanation:
The first hint at the existence of extra dimensions came via Einstein’s theory of general relativity. Almost at a glance, the set of ten general relativity equations indicates an ultimate origin for matter and energy. Even without the detailed calculations, a picture emerges from those equations, a picture of simultaneous expansion and deceleration. Only one phenomenon in physics fits this picture: an explosion. A closer study of these general relativity equations reveals that the entire universe burst forth and is still expanding outward from an infinitely dense state. This creation event, often called the Big Bang, has been confirmed in several ways through the past few decades of research. The most direct evidence comes from measurements of the distances and motions of the galaxies and of the temperature and characteristics of the initial explosion’s radiation residue at varying distances from us. This bursting forth of the cosmos from an infinitely small volume, or essentially an infinitely small volume, implies that the universe has a beginning, a starting point in the finite past. Einstein recognized this implication and dared to say that it affirms the necessity of “a superior reasoning power.” Space-Time Theorem Emerges. Einstein’s conclusion went against the grain of astronomers and physicists trained to presume an infinite universe and an irrelevant, if any, Initiator. The simplicity and obvious nature of his conclusion made it all the more irritating. Several attempts were made to prove that this finite beginning arose from incorrect assumptions about the universe’s homogeneity and symmetry. Critics tried introducing all manner of inhomogeneities, asymmetries, and rotations into Einstein’s theory, but to their amazement, these machinations backfired. They actually slightly shortened the time scale back to the beginning. No matter how astrophysicists manipulated the theory, this stubborn singularity would not go away. It was left to the next generation of astrophysicists to figure out why it would not, could not, go away. Over a four-year period, starting in 1966, George Ellis, Stephen Hawking, and Roger Penrose affirmed that any expanding universe governed by general relativity and which also contains at least some matter and energy must possess a singular origin in the finite past. But they went further. In fact, they carried the solution of Einstein’s equations further than anyone else had. In doing so, they discovered that the operation of general relativity guarantees a singular boundary not just for matter and energy but also for space and time. In other words, if general relativity accurately describes the physics of the universe, both the stuff that makes up the universe and the dimensions in which that stuff exists and operates share a common origin, a finite beginning. We call this finding the space-time theorem of general relativity, and it carries profound philosophical and theological significance. In 1970, however, that crucial if still hung over general relativity. Expansion was no longer in doubt; the existence of matter and energy never had been in doubt. And though the operation of general relativity had been affirmed—to 1 percent precision (two decimal places) —it had not yet been established with adequate certainty to put theoreticians’ doubts to rest. By 1980, the level of certainty had improved to better than a hundredth percent precision (four decimal places)—impressive, and yet still not quite enough to satisfy the most skeptical. But in 1993, the lingering shred of uncertainty finally flew away. The Nobel Prize in physics that year went to Russell Hulse and Joseph Taylor for their study of the binary pulsar PSR 1913+16. This stellar system is unique: two neutron stars (one of which is also a pulsar) orbit closely about one another. Through a twentyyear-long study of this system—in which gravitational forces exceed those seen in our solar system by hundreds of thousands of times—a team lead by Taylor was able to affirm the accuracy of general relativity to better than a trillionth percent precision (that is, to fourteen decimal places). In Penrose’s words, this set of measurements “makes Einstein’s general relativity, in this particular sense, the most accurately tested theory known to science!”
Q. Describe the narrator’s purpose in explaining the super scientific theories and its inconclusiveness. You will be required to write a summary in 100 words; write your points in the form of a connected passage and grid format.