|About the Book|
Albert EinsteinAlbert Einstein was admired for his unique intellect and loved for his great humanity.This unassuming man greeted passersby in his walks along the streets near his home in Princeton, he answered letters from children, and heMoreAlbert EinsteinAlbert Einstein was admired for his unique intellect and loved for his great humanity.This unassuming man greeted passersby in his walks along the streets near his home in Princeton, he answered letters from children, and he counseled statesmen.He warned President Roosevelt of the danger that the Axis powers might be able to make nuclear weapons, and urged an American effort to develop that capability first.After the war he was outspoken about what he saw as the need for the world community to think and act in new ways to avoid nuclear suicide.Already in 1917, during World War I, he wrote, How is it that this culture-loving era could be so monstrously amoral? More and more I come to value charity and love of ones fellow being above everything else.The same Einstein replied to a group of sailors who had written to tell him how their mascot, a cat, came to be named Professor Albert Einstein, as follows: I am sending my heartiest greetings to my namesake, and also from our own tomcat who was very interested in the story and even a little jealous.His reputation for casual dress and untamed hair was well known. Once, being asked about his socks, which did not match, he explained it all. How wrong it would be, he said, if the containers were of a higher quality than the contents.In the bibliography at the end of this book are listed a number of books of a biographical nature. They are highly recommended.About Modern PhysicsPhysics used to be about things that we could see, or at least imagine. Falling and flying objects, things heating and cooling, magnets pushing or pulling, light beams that bend and focus, and later things like radio waves that we could not see but that behaved like things that we could see.Then, as physicists began to probe more deeply, they found that radio waves did not behave like objects that were familiar. When you chased after them, or ran out to meet them, the effect differed fundamentally from the effect of chasing or running out to greet a running child. The difference had to do with the extremely great speed.So began the era of modern physics, that took science into realms that were outside our direct experience. As the theories that physicists had built were applied to things so small, or so fast, that we could no longer easily compare their predictions with familiar experiences, physics changed. Relativity deals with things that move incredibly fast. The math is not what is so difficult about Special Relativity- introductory high school algebra does quite well. Nor did nature spring upon us intricate and complicated new basic principles.The difficulty in understanding Relativity lies largely in trying to imagine things that are outside our experience and that behave in ways our intuition suggests are wrong.For that challenge there is help: a good teacher, or a good book, giving good explanations, good examples, good illustrations.Author Bio: Walter Scheider is the recipient of the Presidential Award for the teaching of Science.He is a graduate of Harvard University, where he also received his PhD. For seventeen years he was a research scientist at the University of Michigan, working on the binding kinetics of small molecules to proteins. He taught physics there, and for twenty years afterwards in the public schools of Ann Arbor, Michigan.He is principal author of articles in the Proceedings of the National Academy of Sciences, the Journal of Physical Chemistry, the Annals of the New York Academy of Sciences, the Biophysical Journal, The Physics Teacher, and The Science Teacher.His program was a nationally designated Exemplary Program of Physics Teaching. He is the recipient of the Lawrence A Conrey Award for Contribution to Science Education, and was twice named to Whos Who Among Americas Teachers.Author Comments: Is there anything new in A serious but not ponderous book about Relativity?Of course not. Special Relativity, at least as far as the non-specialist reader is concerned, is a well travelled subject. Many new books appear every few years on this nearly century old subject.It is in the way it is done, in the insights that are left with the reader, in the thoroughness of presentation, in the readability, and last, but not least, in the skill with which the narrative connects with the readers mind, that any one such book stands out.I have been flattered by readers comments on the writing and on the style.But beyond style is spirit and perspective. There is such a thing as being always meticulously correct, and yet not taking oneself too terribly seriously. You will laugh with me about the tale of Timus Ybatus contested mile run, and yet you will retain, from that example from fantasy, indelibly, the message contained in it about the relation of times measured by observers differently positioned.If you are a non-physicist with a year of high school algebra, you are equipped to handle the math in this book. Necessary concepts that go beyond that are introduced from basic relations. For example, you may have not studied mathematical transformations. To understand relativity, transformation is a key concept. So there is a chapter on what a transformation is, from the bottom up, before the Lorentz transformation is used.The question of math in a book for the general reader is important.Why math?Because without math, it is almost impossible to define the meaning of terms precisely. With only words, the reader infers meanings to words from their common usage in spoken English, although the scientific use of these words may be quite different. Only when terms are defined can they be used beyond the particular sentences in which they appear in a book on relativity. Misunderstanding flourishes in the reading of the no-math books, even while the authors write such books in the hope that the absence of math will make the subject easier to understand.The popular books are necessarily weak in conveying understanding with precision. On the other hand, the more mathematical books on relativity, including the texts, tend to suffer from the excessive reliance on mathematical formalism to tell the story. The lack of talk between author and reader in these books leaves the reader with results that have been arrived at mathematically without the necessary explanation and discussion that almost all of us need.And so, it is not how much math, but in what context and to what purpose is the math present? Math needs to be there to make things precise and well defined, embedded in a wealth of verbal explanation to give significance to the concepts, but never to carry the burden of description alone, or to crowd out the conversation between author and reader.For the non-expert its has been a hard choice to make, between the popular books which, no matter how well done, are forced to pull assertions about relativity out of the blue, and the texts, which drag those same assertions out of a maze of mathematics. In both cases, the reader is left having to accept some of the most counter-intuitive conclusions of relativity on the say-so of experts. The reader whom this book is designed to serve wants something better.I have enjoyed teaching relativity to my students. Mostly they are not physicists and never will be, but they have brains. I have taught, not just lectured on the subject. I have had hundreds of conversations with students and others who are not physicists but have brains, and over more than fifteen years have learned what helps and what doesnt help in the way of explanations, examples, illustrations. It is amazing how hungry so many ordinary citizens are for some understanding of this most fascinating aspect of the world around us. And how absolutely willing they are to have someone to talk to on a level well above the snippets on the news media and the pablum of the popularized books.While relativity books for the generalist are ground out yearly, I believe no one until now has provided the non-physicist with brain a book worthy of that reader, without becoming ponderous.This book began as a set of notes that I duplicated for my students because I found nothing appropriate for them on the bookstore shelves. Gradually these notes grew into this book. If there had not been a gaping hole in the available repertoire, I surely would not have gone to the trouble of doing this. I hope you enjoy reading it as much as I enjoyed creating a serious but not ponderous book about Relativity.