Physics in Fours

There are some very well written textbooks and paperbacks about physics, but the textbooks of necessity often leave out the rich cultural, historical, and conceptual development so essential for a thorough understanding of physics as a body of knowledge and as a human enterprise. And the paperbacks often lack the rigor required for a serious study of physics. Why can't we have our cake and eat it, too? I started writing this as an ancillary textbook and it ended up like a novel. Textbooks are much too long. This venture will not pass 300 pages, and fun, fascinating, new developments in physics will be interspersed throughout. By keeping our focus on four fundamental concepts in physics, the four fundamental forces that govern all interactions, and the four major conservation laws that always hold, we will venture into terrain that offers views across the entire landscape of physics. Now you understand the title of this book! I began writing this book in 1984, six years into my teaching career. Thirty-six years have passed since I typed those first words, and with that passage of time much has changed. I have taught all levels of physics, starting from my brief stint as a teaching and research assistant at WPI in 1978. In the intervening years, I have worked as a physics consultant for the layout designers at Digital Equipment Corporation, as well as a public-school teacher, independent school teacher, coach, Science Department Chair, Dean of Students, and Headmaster at an urban public high school. At the moment, as a semi-retiree, I have spent the last several years teaching physics to mainly biology and chemistry majors at a small liberal arts college. Through it all, my love for teaching and the teaching profession has only grown, despite the best efforts of external "experts" to sap the joy out of the classroom by requiring an endless array of "accountability" measures that serve mainly to detract from excellence in the classroom. Master teachers are virtuoso jazz musicians: constantly improvising within a structure, feeding off the "music" of questions and dialogue to arrive at a deeper understanding of the content, accompanied by a profound sense of wonder at the universe we live in for an entirely too brief a moment in space and time. College teaching has been an absolute blast, and teaching in general is the best career choice I could have made. Emerging from graduate school, and many times since then, I have been constantly reminded about the anxiety most people feel regarding the study of physics. I am still hoping for the day when a conversation concerning what I do for a living goes something like this: "What do you teach?""I teach physics.""Really? Wow, that's great - it's such a creative, vibrant, imaginative field of study!"These days what I usually get is more like this: "Oh, physics. I flunked that in high school. That stuff is way over my head!" I sometimes wander back in time to when we were kids. We asked such great questions about the world. Why is the sky blue? How did all of existence come to be? What produces ocean waves? What was there at the start of the universe? How do we know what we think we know? Hundreds of thoughtful, fundamental questions: where does that innate curiosity go? I think some of that creative spark we all have gets snuffed out the first time we pick up the typical physics textbook: huge, occasionally boring, and frequently inaccessible (financially and otherwise) to the average reader. Worse still, all the fun, the new frontier concepts such as the detection of gravity waves, are usually found at the end of a 1500-page tome, if at all! Why? As a consequence, the typical introductory course syllabus never gets anywhere close to those pages, assuming readers are not comatose by the time they hit page 1000, and students miss out on some extraordinary material. This book aims to rectify that scenario, along with accomplishing several other goals