of the Rainbow to the Edge of Time—A. Journey Through the Wonders of. Physics. Walter Lewin with Warren. Goldstein. Free Press, New York. From the End of the Rainbow to the Edge of Time – A Journey Through the Wonders of Physics Walter Lewin. Download your book. Great video. Read For the Love of Physics by Walter Lewin, Warren Goldstein for free with a 30 day free trial. Read unlimited* books and audiobooks on the web, iPad.
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“Walter Lewin's unabashed passion for physics shines through on every page of “In this fun, engaging, and accessible book, Walter Lewin, a superhero of the. This is one of my favourite book, and professor Walter Lewin is my favourite teacher (I am his student though his You can download in ePUB or PDF format. Walter Lewin, Physics I: Classical Mechanics, Fall (Massachusetts Institute of And it is after that hour that we will do book signing. You can buy the .
Everyone knows that rainbows appear after a storm. The isotopes I was working with typically had half-lives of only a day or a few days. A carpenter made a hatch in the ground floor of our house. Thank you! The Resistance had given him false identification papers, under the name of Jaap Horstman, and my sister and I were instructed to call him Uncle Jaap.
But also, astronomy is physics, writ large across the night sky: Just look up in the sky and ask yourself some obvious questions: Why is the sky blue, why are sunsets red, why are clouds white?
Physics has the answers! The light of the Sun is composed of all the colors of the rainbow. This is called Rayleigh scattering. Blue light scatters the most of all colors, about five times more than red light.
Because the Moon has no atmosphere. Why are sunsets red? For exactly the same reason that the sky is blue. When the Sun is at the horizon, its rays have to travel through more atmosphere, and the green, blue, and violet light get scattered the most—filtered out of the light, basically.
Why are clouds white?
The water drops in clouds are much larger than the tiny particles that make our sky blue, and when light scatters off these much larger particles, all the colors in it scatter equally.
This causes the light to stay white. But if a cloud is very thick with moisture, or if it is in the shadow of another cloud, then not much light will get through, and the cloud will turn dark. I turn all the lights off and aim a very bright spotlight of white light at the ceiling of the classroom near my blackboard. The spotlight is carefully shielded. Then I light a few cigarettes and hold them in the light beam.
The smoke particles are small enough to produce Rayleigh scattering, and because blue light scatters the most, the students see blue smoke. I then carry this demonstration one step further. I inhale the smoke and keep it in my lungs for a minute or so—this is not always easy, but science occasionally requires sacrifices.
I then let go and exhale the smoke into the light beam. The students now see white smoke—I have created a white cloud! The tiny smoke particles have grown in my lungs, as there is a lot of water vapor there.
So now all the colors scatter equally, and the scattered light is white. The color change from blue light to white light is truly amazing! Why is the sky blue, and why are clouds white? Actually, there is also a third very interesting question, having to do with the polarization of light. Out in the country with my students I could show them the Andromeda galaxy, the only one you can see with the naked eye, around 2.
Imagine that— billion stars, and we could just make it out as a faint fuzzy patch. We also spotted lots of meteorites—most people call them shooting stars. The more distant the satellite, and therefore the greater the difference in time between sunset on Earth and at the satellite, the later you can see it at night. The conditions are best only about two dozen evenings and mornings a year.
How wonderful it is when you actually find it! Stargazing connects us to the vastness of the universe. If we keep staring up at the night sky, and let our eyes adjust long enough, we can see the superstructure of the farther reaches of our own Milky Way galaxy quite beautifully—some billion to billion stars, clustered as if woven into a diaphanous fabric, so delightfully delicate.
The size of the universe is incomprehensible, but you can begin to grasp it by first considering the Milky Way. Our current estimate is that there may be as many galaxies in the universe as there are stars in our own galaxy. Or consider the recent discovery of the single largest structure in the known universe, the Great Wall of galaxies, mapped by the Sloan Digital Sky Survey, a major project that has combined the efforts of more than three hundred astronomers and engineers and twenty-five universities and research institutions.
The dedicated Sloan telescope is observing every night; it went into operation in the year and will continue till at least the year The Great Wall is more than a billion light-years long.
Is your head spinning? If not, then consider that the observable universe not the entire universe, just the part we can observe is roughly 90 billion light-years across. This is the power of physics; it can tell us that our observable universe is made up of some billion galaxies. It can also tell us that of all the matter in our visible universe, only about 4 percent is ordinary matter, of which stars and galaxies and you and I are made.
The remaining 73 percent, which is the bulk of the energy in our universe, is called dark energy, which is also invisible. No one has a clue what that is either.
Physics has explained so much, but we still have many mysteries to solve, which I find very inspiring.
Physics explores unimaginable immensity, but at the same time it can dig down into the very smallest realms, to the very bits of matter such as neutrinos, as small as a tiny fraction of a proton. That is where I was spending most of my time in my early days in the field, in the realms of the very small, measuring and mapping the release of particles and radiation from radioactive nuclei.
This was nuclear physics, but not the bomb-making variety. I was studying what made matter tick at a really basic level. You probably know that almost all the matter you can see and touch is made up of elements, such as hydrogen, oxygen, and carbon combined into molecules, and that the smallest unit of an element is an atom, made up of a nucleus and electrons.
A nucleus, recall, consists of protons and neutrons. The lightest and most plentiful element in the universe, hydrogen, has one proton and one electron.
But there is a form of hydrogen that has a neutron as well as a proton in its nucleus. All isotopes of a given element have the same number of protons, but a different number of neutrons, and elements have different numbers of isotopes. There are thirteen isotopes of oxygen, for instance, and thirty-six isotopes of gold. Now, many of these isotopes are stable—that is, they can last more or less forever.
Some of the elements they transform into are stable, and then the radioactive decay stops, but others are unstable, and then the decay continues until a stable state is reached. Of the three isotopes of hydrogen, only one, tritium, is radioactive—it decays into a stable isotope of helium.
If we say that tritium has a half-life of about twelve years, we mean that in a given sample of tritium, half of the isotopes will decay in twelve years only one-quarter will remain after twenty-four years. Nuclear decay is one of the most important processes by which many different elements are transformed and created. In fact, during my PhD research, I was often watching radioactive gold isotopes decay into mercury rather than the other way around, as the medieval alchemists would have liked.
There are, however, many isotopes of mercury, and also of platinum, that decay into gold. But only one platinum isotope and only one mercury isotope decay into stable gold, the kind you can wear on your finger.
The work was immensely exciting; I would have radioactive isotopes literally decaying in my hands. And it was very intense. The isotopes I was working with typically had half-lives of only a day or a few days. Gold, for instance, has a half-life of a little over two and a half days, so I had to work fast. I would drive from Delft to Amsterdam, where they used a cyclotron to make these isotopes, and rush back to the lab at Delft.
There I would dissolve the isotopes in an acid to get them into liquid form, put them on very thin film, and place them into detectors. I was trying to verify a theory about nuclear decay, one that predicted the ratio of gamma ray to electron emissions from the nuclei, and my work required precise measurements.
This work had already been done for many radioactive isotopes, but some recent measurements had come out that were different from what the theory predicted. My supervisor, Professor Aaldert Wapstra, suggested I try to determine whether it was the theory or the measurements that were at fault. It was enormously satisfying, like working on a fantastically intricate puzzle. The challenge was that my measurements had to be much more precise than the ones those other researchers had come up with before me.
And yet physics had provided me with the means to detect and to count them. To get the measurements I needed, I had to milk the sample as long as I could, because the more counts I had, the greater my precision would be. I became a little obsessed. For an experimental physicist, precision is key in everything. This simple, powerful, totally fundamental idea is almost always ignored in college books about physics.
Knowing degrees of accuracy is critical to so many things in our lives. In my work with radioactive isotopes, attaining the degree of accuracy I had to achieve was very challenging, but over three or four years I got better and better at the measurements.
After I improved some of the detectors, they turned out to be extremely accurate. I was confirming the theory, and publishing my results, and this work ended up being my PhD thesis. Many times in physics, and in science generally, results are not always clear-cut. I was fortunate to arrive at a firm conclusion.
I had solved a puzzle and established myself as a physicist, and I had helped to chart the unknown territory of the subatomic world. I was twenty-nine years old, and I was thrilled to be making a solid contribution. I was also fortunate that at the time I got my degree, a whole new era of discovery about the nature of the universe was getting under way. Astronomers were making discoveries at an amazing pace.
Some were examining the atmospheres of Mars and Venus, searching for water vapor. Others had discovered huge, powerful sources of radio waves known as quasars quasi-stellar radio sources. Shortly after, in , astronomers would discover a new category of stars, which came to be called pulsars. I might have continued working in nuclear physics, as there was a great deal of discovery going on there as well. This work was mostly in the hunt for and discovery of a rapidly growing zoo of subatomic particles, most importantly those called quarks, which turned out to be the building blocks of protons and neutrons.
Quarks are so odd in their range of behaviors that in order to classify them, physicists assigned them what they called flavors: The discovery of quarks was one of those beautiful moments in science when a purely theoretical idea is confirmed.
Theorists had predicted quarks, and then experimentalists managed to find them. And how exotic they were, revealing that matter was so much more complicated in its foundations than we had known.
For instance, we now know that protons consist of two up quarks and one down quark, held together by the strong nuclear force, in the form of other strange particles called gluons.
Some theoreticians have recently calculated that the up quark seems to have a mass of about 0. In , I received an invitation from Professor Bruno Rossi at MIT to work on X-ray astronomy, which was an entirely new field, really just a few years old at the time—Rossi had initiated it in MIT was the best thing that could ever have happened to me. Now he had the idea to search the cosmos for X-rays.
Anything went at that time at MIT.
Any idea you had, if you could convince people that it was doable, you could work on it. What a difference from the Netherlands! At Delft, there was a rigid hierarchy, and the graduate students were treated like a lower class.
The professors were given keys to the front door of my building, but as a graduate student you only got a key to the door in the basement, where the bicycles were kept.
Each time you entered the building you had to pick your way through the bicycle storage rooms and be reminded of the fact that you were nothing. The bureaucracy was a real nuisance. The three professors in charge of my institute had reserved parking places close to the front door. One of them, my own supervisor, worked in Amsterdam and came to Delft only once a week on Tuesdays. Since I had to go to Amsterdam to pick up my isotopes, I was allowed 25 cents for a cup of coffee, and 1.
So I asked if I could add the 25 cents to the lunch receipt and only submit one receipt for 1. The department chair, Professor Blaisse, wrote me a letter that stated that if I wanted to have gourmet meals I could do so—at my own expense. So what a joy it was to get to MIT and be free from all of that; I felt reborn. Everything was done to encourage you. I got a key to the front door and could work in my office day or night just as I wanted. To me, that key to the building was like a key to everything.
The head of the Physics Department offered me a faculty position six months after my arrival, in June of When my sister Bea and I talk about it, we almost always cry. I was born in , and I was just four years old when the Germans attacked the Netherlands on May 10, We were holding wet handkerchiefs over our noses, as there had been warnings that there would be gas attacks.
More than a hundred thousand Jews passed through Westerbork, on their way to other camps. The Nazis quickly sent my grandparents to Auschwitz and murdered them—gassed them—the day they arrived, November 19, Westerbork, by contrast, was so strange; it was made to look like a resort for Jews.
There were ballet performances and shops. My mother would often bake potato pancakes that she would then send by mail to our family in Westerbork. Uncle Jenno they sent directly to Buchenwald, where they murdered him—along with more than 55, others. Whenever I see a movie about the Holocaust, which I would not do for a really long time, I project it immediately onto my own family. I still have recurring nightmares about being chased by Nazis, and I wake up sometimes absolutely terrified.
I even once in my dreams witnessed my own execution by the Nazis. Against such a monstrosity, maybe small gestures are all that we have. That, and our refusal to forget: I always use the word murdered, so we do not let language hide the reality. My father was Jewish but my mother was not, and as a Jew married to a non-Jewish woman, he was not immediately a target.
But he became a target soon enough, in I remember that he had to wear the yellow star. Not my mother, or sister, or I, but he did. He had it hidden a little bit, under his clothes, which was forbidden. What was really frightening was the way he gradually accommodated to the Nazi restrictions, which just kept getting worse. Recounting his own exciting discoveries as a pioneer in the field of X-ray astronomy—arriving at MIT right at the start of an astonishing revolution in astronomy—he also brings to life the power of physics to reach into the vastness of space and unveil exotic uncharted territories, from the marvels of a supernova explosion in the Large Magellanic Cloud to the unseeable depths of black holes.
A delightful scientific memoir combined with a memorable introduction to physics. As the hundreds of thousands of students who have witnessed his lectures in person or online can attest, this classroom wizard transforms textbook formulas into magic. For the Love of Physics: Why is a rainbow an arc and not a straight line?
Everyone knows that rainbows appear after a storm. Throughout it all, his sense of wonder is infectious. The excitement of discovery is infectious. In this fun, engaging, and accessible book, Walter Lewin, a superhero of the classroom, uses his powers for good—ours! The authors share the joy of learning that the world is a knowable place.
All rights reserved, including the right to reproduce this book or portions thereof in any form whatsoever. For the love of physics: Lewin, Walter H. College teachers—Massachusetts—Biography. Physics—Study and teaching—Netherlands. Physics—Study and teaching—Massachusetts.
Goldstein, Warren Jay. Six feet two and lean, wearing what looks like a blue work shirt, sleeves rolled to the elbows, khaki cargo pants, sandals and white socks, the professor strides back and forth at the front of his lecture hall, declaiming, gesturing, occasionally stopping for emphasis between a long series of blackboards and a thigh-high lab table.
Four hundred chairs slope upward in front of him, occupied by students who shift in their seats but keep their eyes glued to their professor, who gives the impression that he is barely containing some powerful energy coursing through his body. He halts his stride and turns to the class. All important in making measurements, which is always ignored in every college physics book —he throws his arms wide, fingers spread— is the uncertainty in your measurements.
He pauses, takes a step, giving them time to consider, and stops again: Any measurement that you make without knowledge of the uncertainty is meaningless. Another pause. I will repeat this. He is holding both index fingers to his temples, twisting them, pretending to bore into his brain. They have been exceptionally popular. The ninety-four lectures—in three full courses, plus seven stand-alones—garner about three thousand viewers per day, a million hits a year. You have changed my life, runs a common subject line in the emails Lewin receives every day from people of all ages and from all over the world.
Steve, a florist from San Diego, wrote, I walk with a new spring in my step and I look at life through physics-colored eyes. Professor Lewin you have changed my life Indeed.
The way you teach it is worth 10 times the tuition, and make SOME not all other teachers bunch of criminals. Or Siddharth from India: I could feel Physics beyond those equations.
Your students will always remember you as I will always remember you—as a very-very fine teacher who made life and learning more interesting than I thought was possible. Marjory, another fan, wrote, I watch you as often as I can; sometimes five times per week.
I am fascinated by your personality, your sense of humor, and above all by your ability to simplify matters. I hated physics in high school, but you made me love it. Walter Lewin creates magic when he introduces the wonders of physics.
If I talk about waves on water, I ask them to do certain experiments in their bathtubs; they can relate to that.
They can relate to rainbows. And that can be a wonderful experience—for them and for me. I make them love physics! Sometimes, when my students get really engaged, the classes almost feel like happenings.
He might be perched at the top of a sixteen-foot ladder sucking cranberry juice out of a beaker on the floor with a long snaking straw made out of lab tubing. Or he could be courting serious injury by putting his head in the path of a small but quite powerful wrecking ball that swings to within millimeters of his chin.
He uses his body as a piece of experimental equipment. As he says often, Science requires sacrifices, after all. His son, Emanuel Chuck Lewin, has attended some of these lectures and recounts, I saw him once inhale helium to change his voice. To get the effect right—the devil is in the details—he typically gets pretty close to the point of fainting. An accomplished artist of the blackboard, Lewin draws geometrical figures, vectors, graphs, astronomical phenomena, and animals with abandon.
You can watch it here: A commanding, charismatic presence, Lewin is a genuine eccentric: What about those blue work shirts he wears to class? Not work shirts at all, it turns out. Lewin orders them, custom made to his specifications, of high-grade cotton, a dozen at a time every few years, from a tailor in Hong Kong.
The oversize pocket on the left side Lewin designed to accommodate his calendar. No pocket protectors here—this physicist-performer-teacher is a man of meticulous fashion—which makes a person wonder why he appears to be wearing the oddest brooch ever worn by a university professor: Better, he says, to have egg on my shirt than on my face. What is that oversize pink Lucite ring doing on his left hand? And what is that silvery thing pinching his shirt right at belly-button level, which he keeps sneaking looks at?
Every morning as Lewin dresses, he has the choice of forty rings and thirty-five brooches, as well as dozens of bracelets and necklaces. His taste runs from the eclectic Kenyan beaded bracelets, a necklace of large amber pieces, plastic fruit brooches to the antique a heavy silver Turkmen cuff bracelet to designer and artist-created jewelry, to the simply and hilariously outrageous a necklace of felt licorice candies. The students started noticing, he says, so I began wearing a different piece every lecture.
And especially when I give talks to kids. They love it. And that thing clipped to his shirt that looks like an oversize tie clip? It sometimes seems to others that Lewin is distracted, perhaps a classic absentminded professor. But in reality, he is usually deeply engaged in thinking about some aspect of physics. Those margins were done when he was last lecturing, and he was bored when we were driving. Physics was always on his mind.
His students and school were with him twenty-four hours a day. He seems always to be maximally engaged in whatever he chooses to be involved in, and eliminates 90 percent of the world. Lewin is a perfectionist; he has an almost fanatical obsession with detail. The discoveries he and his colleagues in the field made helped to demystify the nature of the death of stars in massive supernova explosions and to verify that black holes really do exist. For his lectures, he always practiced at least three times in an empty classroom, with the last rehearsal being at five a.
What makes his lectures work, says astrophysicist David Pooley, a former student who worked with him in the classroom, is the time he puts into them. He exploded onto the stage, Leeb recalls, seized us by the brains, and took off on a roller-coaster ride of electromagnetics that I can still feel on the back of my neck.
He is a genius in the classroom with an unmatched resourcefulness for finding ways to make concepts plain. He found the task impossible. The demonstrations were so well woven into the development of the ideas, including a buildup and denouement, that there was no clear time when the demonstration started and when it finished.
To my mind, Walter had a richness of presentation that could not be sliced into bites. He has this ability to get you to see things and to be overwhelmed by how beautiful they are, to stir the pot in you of joy and amazement and excitement. We were on vacation in Maine once. Somehow my father got a little ball and spontaneously created this strange little game, and in a minute some of the other beach kids from next door came over, and suddenly there were four, five, six of us throwing, catching, and laughing.
I remember being so utterly excited and joyful. When guests came for dinner, Walter would preside over the game of Going to the Moon. As Chuck remembers it, We would dim the lights, pound our fists on the table making a drumroll kind of sound, simulating the noise of a rocket launch. Some of the kids would even go under the table and pound. Then, as we reached space, we stopped the pounding, and once we landed on the Moon, all of us would walk around the living room pretending to be in very low gravity, taking crazy exaggerated steps.
Going to the Moon! Walter Lewin has been taking students to the Moon since he first walked into a classroom more than a half century ago. Perpetually entranced by the mystery and beauty of the natural world—from rainbows to neutron stars, from the femur of a mouse to the sounds of music—and by the efforts of scientists and artists to explain, interpret, and represent this world, Walter Lewin is one of the most passionate, devoted, and skillful scientific guides to that world now alive.
In the chapters that follow you will be able to experience that passion, devotion, and skill as he uncovers his lifelong love of physics and shares it with you. Enjoy the journey! I owe a lot to the Dutch educational system. I went to graduate school at the Delft University of Technology in the Netherlands, and killed three birds with one stone. Right from the start, I began teaching physics.
To pay for school I had to take out a loan from the Dutch government, and if I taught full time, at least twenty hours a week, each year the government would forgive one-fifth of my loan. The military would have been the worst, an absolute disaster for me. So I taught math and physics full time, twenty-two contact hours per week, at the Libanon Lyceum in Rotterdam, to sixteen-and seventeen-year-olds.
I avoided the army, did not have to pay back my loan, and was getting my PhD, all at the same time. I also learned to teach. For me, teaching high school students, being able to change the minds of young people in a positive way, that was thrilling.
I always tried to make classes interesting but also fun for the students, even though the school itself was quite strict.