This is the easy, highly simplified introduction to quantumbehavior - and after reading it I still do not understand more than70% of the simplified version! Feynman was both a great physicist anda great communicator, but the subject is both important andperplexingly obscure. This book is based on the Alex G. MautnerMemorial Lectures given at UCLA. Quantum behavior will matter to the21st century the way the steam engine mattered to the 18th and 19thcenturies, the way the internal combustion engine mattered to thefirst two-thirds of the twentieth century, and the way computers andtransistors have mattered to the last third of the twentieth. Tounderstand Quantum behavior you first have to understand themeasurements and scales involved. One billionth of a meter is a"nanometer." It is how we measure things at the level ofmolecules and atoms. Quantum behavior is what starts happening innano-scale behavior below about 50 nanometers. The rules of physicssuddenly change at this level, and the way you and I were taught thatthe world works is suddenly replaced by very different rules. AsFeynman said "my main purpose in these lectures is to describe asaccurately as I can the strange theory of light and matter--morespecifically the interaction of light and electrons." Feynman isclear that the theory works in that it accurately predicts outcomes,but that we do not really understand what is happening or how thoseoutcomes are arrived at. In his words: "What I am going to tellyou about is what we teach our physics students in the third or fourthyear of graduate school ... No, you're not going to be able tounderstand it. Why, then, am I going to bother you with all this? Whyare you going to sit here all this time, when you won't be able tounderstand what I am going to say? It is my task to convince you notto turn away because you don't understand it. You see, my physicsstudents don't understand it either. That is because I don'tunderstand it. Nobody does." Feynman goes on to explain whyquantum behavior is so hard to accept: "I'm going to describe toyou how Nature is--and if you don't like it, that's going to get inthe way of your understanding it. It's a problem that physicists havelearned to deal with. They've learned to realize that whether theylike a theory or they don't like a theory is not the essentialquestion. Rather, it is whether or not the theory gives predictionsthat agree with experiment. It is not a question of whether a theoryis philosophically delightful or easy to understand, or perfectlyreasonable from the point of view of common sense. The theory ofquantum electrodynamics describes Nature as absurd from the point ofview of common sense. And it agrees fully with the experiment. So Ihope you can accept Nature as She is--absurd." Despite itsdifficulty and remarkable characteristics Feynman asserts that Quantumelectrodynamics is important to all of life. Consider: "Most ofthe phenomena you are familiar with involve the interaction of lightand electrons--all of chemistry and biology for example. The onlyphenomena that are not covered by this theory are phenomena ofgravitation and nuclear phenomena; everything else is contained inthis theory." "The more you see how strangely Naturebehaves, the harder it is to make a model that explains how even thesimplest phenomena actually work" is a Feynman observation thatgoes to the heart of our current situation. In traditional areas ofscience we are making rapid progress and some people think we are evenclose to the end of the scientific era or in a mature state. Yet inmany areas of science we are just beginning to understand thequestions and do not have a clue as to the answers. For example, 80%of the universe is dark matter and we currently know nothing aboutdark matter. Feynman's book is a good introduction to the frontiersthat beckon us to a great age of discovery in the 21stcentury. Consider the possibility that at least at very tiny levelsa kind of time travel can occur. Here is the description of figure 63(p.96) "the scattering of light involves a photon going into anelectron and a photon coming out--not necessarily in that order, asseen in example b. The example in c shows a strange but realpossibility; the electron emits a photon, rushes backwards in time toabsorb a photon, and then continues forward in time." Rememberthis is a great physicist lecturing a sophisticated general audienceabout the cutting edge of knowledge. There is much in this onedescription to think about. Feynman goes further on this topic:"This phenomenon is general. Every particle in Nature has anamplitude to move backwards in time, and therefore has ananti-particle." Feynman's argument is that quantum behavior istruly outside the Newtonian principles of classical physics andcontradicts our understanding of the world as we experience it at ourlarge, bulky level. "Throughout these lectures I have delightedin showing you that the price of gaining such an accurate theory hasbeen the erosion of our common sense. We must accept some very bizarrebehavior...light traveling in paths other than a straight line,photons going faster or slower than the conventional speed of light,electrons going backwards in time...That we must do, in order toappreciate what Nature is really doing underneath nearly all thephenomena we see in the world." This is a challenging but veryimportant book about a topic which will have enormous implications forour century but which remarkably few public minded citizens have paidany attention to. I strongly recommend it.
23 people found this helpful.
Was this review helpful to you?