This title has been withdrawn from MIT Press Direct. Please follow the "Buy in Print Options" link for other ways to obtain this book. Drawings and short essays offer engaging and accessible explanations of key ideas in physics, from triangulation to relativity and beyond.Humans have been trying to understand the physical universe since antiquity. Aristotle had one vision (the realm of the celestial spheres is perfect), and Einstein another (all motion is relativistic). More often than not, these different understandings begin with a simple drawing, a pre-mathematical picture of reality. Such drawings are a humble but effective tool of the physicist's craft, part of the tradition of thinking, teaching, and learning passed down through the centuries. This book uses drawings to help explain fifty-one key ideas of physics accessibly and engagingly. Don Lemons, a professor of physics and author of several physics books, pairs short, elegantly written essays with simple drawings that together convey important concepts from the history of physical science.Lemons proceeds chronologically, beginning with Thales' discovery of triangulation, the Pythagorean monocord, and Archimedes' explanation of balance. He continues through Leonardo's description of "earthshine" (the ghostly glow between the horns of a crescent moon), Kepler's laws of planetary motion, and Newton's cradle (suspended steel balls demonstrating by their collisions that for every action there is always an equal and opposite reaction). Reaching the twentieth and twenty-first centuries, Lemons explains the photoelectric effect, the hydrogen atom, general relativity, the global greenhouse effect, Higgs boson, and more. The essays place the science of the drawings in historical context—describing, for example, Galileo's conflict with the Roman Catholic Church over his teaching that the sun is the center of the universe, the link between the discovery of electrical phenomena and the romanticism of William Wordsworth, and the shadow cast by the Great War over Einstein's discovery of relativity. Readers of Drawing Physics with little background in mathematics or physics will say, "Now I see, and now I understand."
This title has been withdrawn from MIT Press Direct. Please follow the "Buy in Print Options" link for other ways to obtain this book. Drawings and short essays offer engaging and accessible explanations of key ideas in physics, from triangulation to relativity and beyond.Humans have been trying to understand the physical universe since antiquity. Aristotle had one vision (the realm of the celestial spheres is perfect), and Einstein another (all motion is relativistic). More often than not, these different understandings begin with a simple drawing, a pre-mathematical picture of reality. Such drawings are a humble but effective tool of the physicist's craft, part of the tradition of thinking, teaching, and learning passed down through the centuries. This book uses drawings to help explain fifty-one key ideas of physics accessibly and engagingly. Don Lemons, a professor of physics and author of several physics books, pairs short, elegantly written essays with simple drawings that together convey important concepts from the history of physical science.Lemons proceeds chronologically, beginning with Thales' discovery of triangulation, the Pythagorean monocord, and Archimedes' explanation of balance. He continues through Leonardo's description of "earthshine" (the ghostly glow between the horns of a crescent moon), Kepler's laws of planetary motion, and Newton's cradle (suspended steel balls demonstrating by their collisions that for every action there is always an equal and opposite reaction). Reaching the twentieth and twenty-first centuries, Lemons explains the photoelectric effect, the hydrogen atom, general relativity, the global greenhouse effect, Higgs boson, and more. The essays place the science of the drawings in historical context—describing, for example, Galileo's conflict with the Roman Catholic Church over his teaching that the sun is the center of the universe, the link between the discovery of electrical phenomena and the romanticism of William Wordsworth, and the shadow cast by the Great War over Einstein's discovery of relativity. Readers of Drawing Physics with little background in mathematics or physics will say, "Now I see, and now I understand."
Abstract This chapter introduces the book by emphasizing how our perception of the universe is quite different from the actual laws that govern this universe. An attempt to understand the laws that govern our universe goes back to antiquity. The modern scientific revolution took place in the seventeenth century. All the phenomena that we observe in nature seem to follow the laws that were discovered by Newton, Maxwell, and others. Our intuition is based on these laws. The most remarkable developments that took place at the beginning of the twentieth century included Einstein’s theory of relativity and quantum mechanics. These laws, which are presented in this book, are highly counterintuitive and mysterious.
The two towering achievements of modern physics are quantum theory and Einstein's general theory of relativity. Together, they explain virtually everything about the world we live in. But, almost a century after their advent, most people haven't the slightest clue what either is about. Did you know that there's so much empty space inside matter that the entire human race could be squeezed into the volume of a sugar cube? Or that you grow old more quickly on the top floor of a building than on the ground floor? And did you realize that 1% of the static on a TV tuned between stations is the relic of the Big Bang? These and many other remarkable facts about the world are direct consequences of quantum physics and relativity. Quantum theory has literally made the modern world possible. Not only has it given us lasers, computers, and nuclear reactors, but it has provided an explanation of why the sun shines and why the ground beneath our feet is solid. Despite this, however, quantum theory and relativity remain a patchwork of fragmented ideas, vaguely understood at best and often utterly mysterious. They have even gained a reputation of being beyond the understanding of the average person. Author Marcus Chown emphatically disagrees. As Einstein himself said, Most of the fundamental ideas of science are essentially simple and may, as a rule, be expressed in a language comprehensible to everyone. If you think that the marvels of modern physics have passed you by, it is not too late. In Chown's capable hands, quantum physics and relativity are not only painless but downright fun. So sit back, relax, and get comfortable as an adept and experienced science communicator brings you quickly up to speed on some of the greatest ideas in the history of human thought.
The announcement in 2012 that the Higgs boson had been discovered was understood as a watershed moment for the Standard Model of particle physics. It was deemed a triumphant event in the reductionist quest that had begun centuries ago with the ancient Greek natural philosophers. Physicists basked in the satisfaction of explaining to the world that the ultimate cause of mass in our universe had been unveiled at CERN, Switzerland. The Standard Model of particle physics is now understood by many to have arrived at a satisfactory description of entities and interactions on the smallest physical scales: elementary quarks, leptons, and intermediary gauge bosons residing within a four-dimensional spacetime continuum. Throughout the historical journey of reductionist physics, mathematics has played an increasingly dominant role. Indeed, abstract mathematics has now become indispensable in guiding our discovery of the physical world. Elementary particles are endowed with abstract existence in accordance with their appearance in complicated equations. Heisenberg’s uncertainty principle, originally intended to estimate practical measurement uncertainties, now bequeaths a numerical fuzziness to the structure of reality. Particle physicists have borrowed effective mathematical tools originally invented and employed by condensed matter physicists to approximate the complex structures and dynamics of solids and liquids and bestowed on them the authority to define basic physical reality. The discovery of the Higgs boson was a result of these kinds of strategies, used by particle physicists to take the latest steps on the reductionist quest. This book offers a constructive critique of the modern orthodoxy into which all aspiring young physicists are now trained, that the ever-evolving mathematical models of modern physics are leading us toward a truer understanding of the real physical world. The authors propose that among modern physicists, physical realism has been largely replaced—in actual practice—by quasirealism, a problematic philosophical approach that interprets the statements of abstract, effective mathematical models as providing direct information about reality. History may judge that physics in the twentieth century, despite its seeming successes, involved a profound deviation from the historical reductionist voyage to fathom the mysteries of the physical universe.
Even the experts do not understand it the way they would like to, and it is perfectly reasonable that they should not, because all of direct, human experience and of human intuition applies to large objects. Richard P. Feynman Two great intellectual triumphs occurred in the first quarter of the twentieth century: the invention of the theory of relativity, and the rather more labored arrival of quantum mechanics. The former largely embodies the ideas, and almost exclusively the vision, of Albert Einstein; the latter benefited from many creative minds, and from a constant interplay between theory and experiment. Probability plays no direct role in relativity, which is thus outside the purview and purpose of this book. However, Einstein will make an appearance in the following pages, in what some would claim was his most revolutionary role – as diviner of the logical and physical consequences of every idea that was put forward in the formative stages of quantum mechanics. It is one of the ironies of the history of science that Einstein, who contributed so importantly to the task of creating this subject, never accepted that the job was finished when a majority of physicists did. As a consequence, he participated only indirectly in the great adventure of the second quarter of the century: the use of quantum mechanics to explain the structure of atoms, nuclei, and matter.
1124 NOTICES OF THE AMS VOLUME 45, NUMBER 9 I n the twentieth century, the quest for deeper understanding of the laws of nature has largely revolved around the development of two great theories: namely, general relativity and quantum mechanics. General relativity is, of course, Einstein’s theory according to which gravitation results from the curvature of space and time; the mathematical framework is that of Riemannian geometry. While previously spacetime was understood as a fixed arena, given ab initio, in which physics unfolds, in general relativity spacetime evolves dynamically, according to the Einstein equations. Part of the problem of physics, according to this theory, is to determine, given the initial conditions as input, how spacetime will develop in the future. The influence of general relativity in twentiethcentury mathematics has been clear enough. Learning that Riemannian geometry is so central in physics gave a big boost to its growth as a mathematical subject; it developed into one of the most fruitful branches of mathematics, with applications in many other areas. While in physics general relativity is used to understand the behavior of astronomical bodies and the universe as a whole, quantum mechanics is used primarily to understand atoms, molecules, and subatomic particles. Quantum theory has had a much more complex history than general relativity, and in some sense most of its influence on mathematics belongs to the twenty-first century. The quantum theory of particles—which is more commonly called nonrelativistic quantum mechanics—was put in its modern form by 1925 and has greatly influenced the development of functional analysis, and other areas. But the deeper part of quantum theory is the quantum theory of fields, which arises when one tries to combine quantum mechanics with special relativity (the precursor of general relativity, in which the speed of light is the same in every inertial frame but spacetime is still flat and given ab initio). This much more difficult theory, developed from the late 1920s to the present, encompasses most of what we know of the laws of physics, except gravity. In its seventy years there have been many milestones, ranging from the theory of “antimatter”, which emerged around 1930, to a more precise description of atoms, which quantum field theory provided by 1950, to the “standard model of particle physics” (governing the strong, weak, and electromagnetic interactions), which emerged by the early 1970s, to new predictions in our own time that one hopes to test in present and future accelerators. Quantum field theory is a very rich subject for mathematics as well as physics. But its development in the last seventy years has been mainly by physicists, and it is still largely out of reach as a rigorous mathematical theory despite important efforts in constructive field theory. So most of its impact on mathematics has not yet been felt. Yet in many active areas of mathematics, problems are Edward Witten is professor of physics at the Institute for Advanced Study. His e-mail address is witten@ias.edu.
‘God’, said Albert Einstein, ‘does not play dice’. This famous remark by the author of the theory of relativity was not intended as an analysis of the recreational habits of a supreme being but expressed his reaction to the new scientific ideas, developed in the first quarter of the twentieth century, which are now known as quantum physics. Before we can fully appreciate why one of the greatest scientists of modern times should have been led to make such a comment, we must first try to understand the context of scientific and philosophical thought that had become established by the end of the nineteenth century and what it was about the ‘new physics’ that presented such a radical challenge to this consensus. What is often thought of as the modern scientific age began in the sixteenth century, when Nicholas Copernicus proposed that the motion of the stars and planets should be described on the assumption that it is the sun, rather than the earth, which is the centre of the solar system. The opposition, not to say persecution, that this idea encountered from the establishment of that time is well known, but this was unable to prevent a revolution in thinking whose influence has continued to the present day. From that time on, the accepted test of scientific truth has increasingly been observation and experiment rather than religious or philosophical dogma.