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1 Physics and Sociecy Physics is the science of the most fundamental aspects of nature. The realms of physics span distances from the subnuclear world of elemen- tary particles to the whole of the cosmos, and times from less than a billionth of a trillionth of a second to the age of the universe. To study phenomena across these epochal scales, to devise experimental tools that provide ever more powerful means for viewing nature, and to create theories that allow us to comprehend what has been seen these are the goals and the achievements of physics. In deepening our view of nature, physics has profoundly affected our view of mankind because the underlying assumption of physics that there is order in the natural world and that the human mind can understand that order- permeates modern thought. By generating new technologies and by contributing to neighboring sciences, physics has helped to transform our daily lives, permitting a comfort and freedom of action that make it difficult to comprehend that little more than a century ago, even in the technically advanced nations, most people devoted most of their energy to securing food and shelter. Physics has done much to mold the shape of modern society. The search to understand elementary phenomena has led to expanded views of all nature and to miraculous inventions. The path of this search is unpredictable, but along it the history of physics offers many examples. To cite one of these, starting in the eighteenth and nine- teenth centuries, scientists like Cavendish, Franklin, Ampere, and 6
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PHYSICS AND SOCIETY 7 Faraday carried out painstaking experiments on electrical and mag- netic phenomena. Their observations provided the foundation for James Clerk Maxwell's electromagnetic theory. Maxwell discovered that light is a natural manifestation of familiar electrical and magnetic forces. To find a connection between light and everyday forces was a triumph of modern thought. From Maxwell's work we have gained a deep understanding of electromagnetic phenomena from waves to plasmas and the answers to questions ranging from why air is trans- parent to how radiative energy transport determines solar and stellar equilibrium. Electromagnetic theory underlies the invention of radio, television, and radar and makes possible the creation of our vast industrial power networks and modern communications systems. In fact, it is difficult to cite instances of modern life that have not been touched in some way by Maxwell's discovery. The creation of quantum mechanics in the 1920s provides a second example of the unpredictable path by which new knowledge in physics can shape society. Based on studies of the properties of matter, the spectra of atoms, and the motions of charged particles, quantum mechanics provided an extraordinary new framework for portraying physical reality. Quantum mechanics revolutionized our most funda- mental concepts of measurement and paved the way to understanding the structure of atoms, molecules, and solids. It is now recognized that quantum mechanics is basic not only to physics but to chemistry, biology, and many of the other sciences. Beyond this, quantum mechanics has led to the creation of new industries, such as semicon- ductors and optical communications, and has opened new paths of technology through the creation of exotic materials and devices like the laser. The discoveries of electromagnetic theory and quantum mechanics are now part of history, but seminal advances in physics continue. A few decades ago no one realized that cosmology and astrophysics were on the threshold of a golden age and that radioastronomy, x-ray astronomy, and other new techniques were about to yield pictures of the universe that would make our previous views seem blurred and shadowy images. A marvelous scenario of the origin of the universe and its eventual fate is now being constructed from these pictures. The new theories cannot help but eventually affect our total vision of our role in nature and deepen our understanding and appreciation of life. Another advance can be traced to the study of electronic materials known as semiconductors. The discovery in 1947 by Shockley, Bardeen, and Brattain of the transistor eject paved the way for the computer revolution that is taking place around us today. Nobody can
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8 PHYSICS THROUGIl THE 1990s: AN OVERVIEW know how society will ultimately be transformed by this revolution, but the advances have been so rapid that the image of a savings bank with clerks patiently entering transactions by hand, without the benefit of automatic data processing, seems almost as remote as a candlelit counting house in a novel by Dickens. Before World War II, physics was essentially a European activity, but by the war's end, the center of physics had moved to the United States. The influx of European physicists, a generation of outstanding young American physicists, and the heritage of intense cooperation between science and government that grew out of the nation's efforts to develop radar and the atomic bomb presented the United States with a scientific community of unsurpassed quality. Discoveries by this community since World War II rank among the greatest achievements of physics. They include the creation of quantum electrodynamics, the theory of superconductivity, the discovery of remnants from the primordial explosion at the birth of the universe, and the invention of the transistor and the laser. The role of physics in the United States today is complex. Curiosity and the basic need for understanding remain the intellectual driving force for physics, but physics also affects society broadly through its interactions with all the natural sciences, with technology and engi- neering, and with medicine. To strengthen these, physics provides conceptual tools, experimental techniques, and new materials. Much of our advanced technology can be traced directly to basic research in physics. Optical communications and laser-assisted manufacturing exemplify technologies that will play a vital role in helping the nation to retain its industrial competitiveness in the years to comes Biophysics, molecular biology, and physiology three sciences that closely underlie medicine all use concepts and experimental tech- niques from physics. Nuclear medicine, radiation therapy, x-ray to- mography, and laser surgery are but a few of physics' many contribu- tions to medical diagnosis and therapy. One of the most recent diagnostic techniques, magnetic resonance imaging (MRI), allows doctors to peer into the human body as clearly as they can view its surface (Figure 1.1~. MRI is nonperturbing, noninvasive, and free of any known side effects. Its role in medical diagnosis is expected to be revolutionary, comparable in effect to the discovery of x rays. The creation of MRI required microcomputers whose origin depended on the invention of the transistor- and superconducting magnets which were created from research in low-temperature physics. The basic principles of MRI, however, were discovered in pioneering research by Purcell and Bloch, who were simply curious about how nuclei magnet-
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PHYSICS AND SOCIETY 9 FIGURE 1.1 Proton magnetic resonance image showing a sagittal slice of cranial anatomy demonstrating an enlarged pituitary gland. The image was obtained on a Technicare 1.5-tesla Teslacon magnetic resonance system at the Cleveland Clinic using a spin-echo pulse technique. The phenomena of nuclear magnetic resonance, solid-state microelectronics, and superconducting materials for high field magnets, which combine to make the medical magnetic resonance imager, are all products of physics research of the past four decades. ically interact with matter. The benefits now Bowing from their work illustrate the large returns in human well-being that may come from basic research by scientists with the freedom and the resources to pursue the search for fundamental understanding. Physics has given mankind the power to make life better or to destroy it. How to use this power wisely has become society's most urgent challenge. To meet it successfully will require a public educated in the underlying science and a political leadership well informed about scientific issues and technical options. Physicists must play an essential role in advising and counseling. The United States is a leader in the community of nations. Our economic vitality and our national security system are visible signs of our strength, but our authority stems ultimately from the political and
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10 PHYSICS THROUGH THE 1990s: AN OVERVIEW social ideals that animate us and from our cultural and intellectual accomplishments. Our achievements in physics are respected by people everywhere; they help the United States to fulfill its role as a world leader. Physics in the United States has become a federal responsibility. Universities, industry, and private institutions all participate in physics research, but the federal government has assumed major responsibility for its support. This assumption reflects the essential role that physics plays in generating new technologies and in maintaining our national defense. It also reflects a widespread public interest in science, an excitement over new discoveries, and a national pride in accomplish- ment. Advanced technology, in this age of robotics and the information explosion, is a major driving force behind economic growth in the developed countries. Looking to the future, the United States must be able to meet the challenge of creating the new technology needed to sustain growth. And the other nations of the world must be able to meet the challenges posed by the growth of population, the pressure on nonrenewable resources, and the increasing burden on the environ- ment. Many nations will look to the United States for help in providing the new technologies required to solve their problems. If the world is to live in peace, we must meet these challenges. Basic science is the driving force of the new technology; the role that physics can play is critical to the future of mankind.
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