Topic “Pure intellectual stimulation that can be popped into Science Subtopic the [audio or video player] anytime.” & Mathematics Physics —Harvard Magazine Physics and Our Universe: Physics and Our Universe “Passionate, erudite, living legend lecturers. Academia’s best lecturers are being captured on tape.” —The Los Angeles Times “A serious force in American education.” How It All Works —The Wall Street Journal Course Guidebook Professor Richard Wolfson Middlebury College Professor Richard Wolfson is the Benjamin F. Wissler Professor of Physics at Middlebury College. He is an expert at interpreting concepts in physics, climatology, and engineering for the nonspecialist.
He is also the author of several books, including Essential University Physics and Simply Einstein: Relativity Demystified. THE GREAT COURSES ® Corporate Headquarters 4840 Westfields Boulevard, Suite 500 Chantilly, VA 20151-2299 Guidebook USA Phone: 1-800-832-2412 www.com Cover Image: © Warren Faidley/Corbis. 1280 © 2011 The Teaching Company.com PUBLISHED BY: THE GREAT COURSES Corporate Headquarters 4840 Westfields Boulevard, Suite 500 Chantilly, Virginia 20151-2299 Phone: 1-800-832-2412 Fax: 703-378-3819 www.com Copyright © The Teaching Company, 2011 Printed in the United States of America This book is in copyright. All rights reserved.
Without limiting the rights under copyright reserved above, no part of this publication may be reproduced, stored in or introduced into a retrieval system, or transmitted, in any form, or by any means (electronic, mechanical, photocopying, recording, or otherwise), without the prior written permission of The Teaching Company.com Richard Wolfson, Ph. Wissler Professor of Physics Middlebury College P rofessor Richard Wolfson is the Benjamin F. Wissler Professor of Physics at Middlebury College, and he also teaches in Middlebury’s Environmental Studies Program. He did undergraduate work at the Massachusetts Institute of Technology and Swarthmore College, graduating from Swarthmore with bachelor’s degrees in Physics and Philosophy.
He holds a master’s degree in Environmental Studies from the University of Michigan and a doctorate in Physics from Dartmouth. Professor Wolfson’s books Nuclear Choices: A Citizen’s Guide to Nuclear Technology (MIT Press, 1993) and Simply Einstein: Relativity Demysti¿ed (W. Norton, 2003) exemplify his interest in making science accessible to nonscientists. His textbooks include 3 editions of Physics for Scientists and Engineers, coauthored with Jay M.
Pasachoff; 2 editions of Essential University Physics (Addison-Wesley, 2007, 2010); 2 editions of Energy, Environment, and Climate (W. Norton, 2008, 2012); and Essential College Physics (Addison-Wesley, 2010), coauthored with Andrew Rex. Professor Wolfson has also published in Scienti¿c American and writes for World Book Encyclopedia. Professor Wolfson’s current research involves the eruptive behavior of the Sun’s corona, as well as terrestrial climate change.
His other published work encompasses such diverse ¿elds as medical physics, plasma physics, solar energy engineering, electronic circuit design, nuclear issues, observational astronomy, and theoretical astrophysics. In addition to Physics and Our Universe: How It All Works, Professor Wolfson has produced 3 other lecture series for The Great Courses, including Einstein’s Relativity and the Quantum Revolution: Modern Physics for Non-Scientists, Physics in Your Life, and Earth’s Changing Climate. He has i www.com also lectured for the One Day University and Scienti¿c American’s Bright Horizons cruises. Professor Wolfson has spent sabbaticals at the National Center for Atmospheric Research, the University of St.
Andrews, and Stanford University. In 2009, he was elected an American Physical Society Fellow.com Table of Contents INTRODUCTION Professor Biography .1 LECTURE GUIDES LECTURE 1 The Fundamental Science.4 LECTURE 2 Languages of Physics .9 LECTURE 3 Describing Motion .14 LECTURE 4 Falling Freely .19 LECTURE 5 It’s a 3-D World! .23 LECTURE 6 Going in Circles .28 LECTURE 7 Causes of Motion.32 LECTURE 8 Using Newton’s Laws—1-D Motion .37 LECTURE 9 Action and Reaction .42 LECTURE 10 Newton’s Laws in 2 and 3 Dimensions .com Table of Contents LECTURE 11 Work and Energy .52 LECTURE 12 Using Energy Conservation .64 LECTURE 14 Systems of Particles .70 LECTURE 15 Rotational Motion.76 LECTURE 16 Keeping Still.82 LECTURE 17 Back and Forth—Oscillatory Motion .88 LECTURE 18 Making Waves .94 LECTURE 19 Fluid Statics—The Tip of the Iceberg .101 LECTURE 20 Fluid Dynamics .107 LECTURE 21 Heat and Temperature. 113 LECTURE 22 Heat Transfer. 119 LECTURE 23 Matter and Heat .com Table of Contents LECTURE 24 The Ideal Gas .131 LECTURE 25 Heat and Work.137 LECTURE 26 Entropy—The Second Law of Thermodynamics .143 LECTURE 27 Consequences of the Second Law .148 LECTURE 28 A Charged World .154 LECTURE 29 The Electric Field .160 LECTURE 30 Electric Potential .166 LECTURE 31 Electric Energy .172 LECTURE 32 Electric Current .178 LECTURE 33 Electric Circuits .191 LECTURE 35 The Origin of Magnetism .198 LECTURE 36 Electromagnetic Induction .com Table of Contents LECTURE 37 Applications of Electromagnetic Induction.
211 LECTURE 38 Magnetic Energy.216 LECTURE 39 AC/DC .222 LECTURE 40 Electromagnetic Waves .228 LECTURE 41 ReÀection and Refraction .240 LECTURE 43 Wave Optics .245 LECTURE 44 Cracks in the Classical Picture .253 LECTURE 45 Earth, Ether, Light .259 LECTURE 46 Special Relativity .264 LECTURE 47 Time and Space .270 LECTURE 48 Space-Time and Mass-Energy .com Table of Contents LECTURE 49 General Relativity .283 LECTURE 50 Introducing the Quantum .289 LECTURE 51 Atomic Quandaries .295 LECTURE 52 Wave or Particle? .301 LECTURE 53 Quantum Mechanics.313 LECTURE 55 Molecules and Solids.319 LECTURE 56 The Atomic Nucleus.325 LECTURE 57 Energy from the Nucleus .331 LECTURE 58 The Particle Zoo .337 LECTURE 59 An Evolving Universe .343 LECTURE 60 Humble Physics—What We Don’t Know .com Table of Contents SUPPLEMENTAL MATERIAL Glossary .com Physics and Our Universe: How It All Works Scope: P hysics is the fundamental science. Its principles govern the workings of the universe at the most basic level and describe natural phenomena as well as the technologies that enable modern civilization. Physics is an experimental science that probes nature to discover its secrets, to re¿ne our understanding, and to explore new and useful applications. It’s also a quantitative science, written elegantly in the language of mathematics—a language that often permits us to predict and control the physical world with exquisite precision.
Physics is a theoretical science, meaning that a few overarching “big ideas” provide solidly veri¿ed frameworks for explanation of broad ranges of seemingly disparate phenomena. Our current understanding of physics traces to the work of Galileo and Newton in the 16th, 17th, and 18th centuries. Overthrowing 2000 years of misconceptions, these scientists laid the groundwork for the description of motion—a phenomenon at the heart of essentially everything that happens. The result is Newtonian mechanics: a simple, coherent theory expressed in 3 basic laws that even today describes most instances of motion we deal with in everyday life and, indeed, in much of the universe beyond Earth.
Newtonian mechanics introduces some great ideas that continue throughout physics, even into realms where Newtonian ideas no longer apply. Concepts of force, energy, momentum, and conservation laws are central to all realms of physics—and all trace their origins to Newtonian mechanics. Galileo and Newton are also responsible for the ¿rst great uni¿cation in physics, as their ideas brought the terrestrial and celestial realms under a common set of physical laws. Newton’s law of universal gravitation recognized that a universal attractive force, gravity, operates throughout the entire universe.
Newton provided a mathematical description of that force, developed calculus to explore the rami¿cations of his idea, and showed de¿nitively why the planets of our Solar System move as they do. Although Newtonian mechanics is more than 300 years old, it governs modern technologies ranging from skyscrapers to automobiles to spacecraft. This course begins, appropriately, with an exploration of Newtonian mechanics.com Motion manifests itself in more subtle ways than a car zooming down the highway or a planet orbiting the Sun. Wave motion transports energy but not matter; examples include ocean waves, seismic waves emanating from earthquakes, and sound.
Liquids and gases, collectively called Àuids, exhibit a wide range of motions, some strikingly beautiful and others—like the winds of a hurricane or the blast of a jet engine—awesomely powerful. Random motions of atoms and molecules are at the basis of thermodynamics, the science of heat and related phenomena. Thermodynamics governs many of the energy Àows in the universe, from the outpouring of energy that lights the stars to Earth’s complex climate system to the technologies we use to power modern society. Thermodynamics presents fundamental limitations on our ability to extract energy from fuels—limitations at the heart of today’s energy concerns.
Most phenomena of wave motion, Àuid motion, and thermodynamics are ultimately explained in terms of Newtonian mechanics—a realization that gradually evolved in the centuries after Newton. Electromagnetism is one of the fundamental forces in the universe and the dominant interaction on scales from atoms to our own bodies. Today, electrical and electronic technologies are indispensable; they range from the powerful motors that run our subways, high-speed railroads, and hybrid cars to the microchips that enable smart phones to have more computing power than the supercomputers of the late 20th century. Electromagnetism is also responsible for the forces that bind atoms into molecules and for molecular interactions that include, among many others, the replication of DNA allowing life to continue.
Intimately related, electricity and magnetism together make possible electromagnetic waves. These waves provide nearly all the knowledge we have of the cosmos beyond our home planet, transport to Earth the solar energy that sustains life, and tie us increasingly to each other with a web of wireless communication—from traditional radio and television to cellular phone networks, GPS satellites, and wireless internet connectivity. As James Clerk Maxwell recognized in the mid-1800s, light is an electromagnetic wave—a realization that brought the science of optics under the umbrella of electromagnetism. This course devotes 12 lectures to electromagnetism.com Optics deals with the behavior of light.
Phenomena of reÀection, refraction, and interference are crucial to understanding and exploiting light. Eyeglasses, contact lenses, and laser vision correction all depend on optical principles—and so do the microscopes and telescopes that extend our vision to the interiors of living cells and to the most remote galaxies. DVD and Blu- ray discs store full-length movies in optically readable formats, and lasers exploit optics in applications from scanning barcodes to cutting metal. A total of 4 lectures explore optical principles and their applications.
Newtonian mechanics and electromagnetism comprise classical physics—a realm of physics whose theoretical background was in place before the year 1900 but that nevertheless remains relevant in much contemporary science and in many cutting-edge technologies. By 1900, physicists recognized seemingly subtle discrepancies between experimental results and classical physics. In the early decade of the 20th century, these discrepancies led to 2 revolutions in physics. Einstein’s special and general theories of relativity radically altered our notions of space, time, and gravity.
Quantum mechanics overthrew deep-seated classical ideas of determinism and causality. Together, relativity and quantum physics laid the groundwork for our modern understanding of the universe—the particles and ¿elds that comprise it, the forces that bind components of it, and the interactions of those forces at the largest and smallest scales. This course ends with these revolutionary ideas and their applications today to cosmology, elementary particle physics, string theory, black holes, nanotechnology, and other topics at the cutting edge of modern physics.com Section 0: Introduction The Fundamental Science Lecture 1 P hysics is at the heart of our understanding of physical reality. Principles of physics apply universally—from the behavior of the in¿nitesimally tiny quarks that comprise the protons and neutrons of the atomic nucleus to the ordering of matter into galaxies, galaxy clusters, and superclusters at the largest scales imaginable.
Physics also lays the groundwork for the other sciences, especially chemistry and biology. Nevertheless, emergent properties in complex systems mean that physics alone cannot provide a complete and comprehensible description of chemical and biological phenomena. x Physics is the fundamental science; it’s the most basic description we have of physical reality. x Physics covers everything from the tiny subatomic particles called quarks and leptons to the stars, galaxies, clusters of galaxies, and large-scale structure of the entire universe itself.