For the Love of Physics
Walter Lewin. How much I love you. Your crazy hair, your crazy stunts, the fact that you clearly love nothing in the world as much as you love physics. Since, as you say, physics explains the world, that makes a lot of sense. And I totally agree with you. We both know, however, that lots of people don’t. To lots of people, there is nothing more boring than a blackboard covered in equations. As much as I love physics, I love teaching people about physics (and science in general) even more. I love telling kids something fun, about bubbles, or trees, or their own skin, and watching their eyes light up as they process their new knowledge. I love showing my friends cool random things about the world around us.
Like this silly putty with magnetic flecks “eating” a magnet:
Or giant bubbles attached to each other:
When I saw Walter Lewin’s book For the Love of Physics in the library, I recognized him immediately. I opened it up, to read the first few paragraphs, as I usually do in the library, and all of a sudden I was at Chapter 2. I loved his explanation for blue and white smoke (explaining why the sky is blue and the clouds are white) almost as much as I loved the first time I watched him swing across the classroom on a pendulum.
The book’s purpose is clear: to get non-scientists interested and fascinated by the world around them. Because the sad reality is that the majority of Americans not only don’t know much about physics, but they dislike physics, and the sciences in general, so much that the mere mention of science makes them turn away in disgust. And in accomplishing that, I think the book succeeds. Full of personal anecdotes and fun mini-experiments, the book is interesting from start to finish. He inserts urls with regularity – links to videos and information, encouraging people who find the topic interesting to go learn more about it. For me, though, the book was a bit boring. There were no calculations, there was no real math (even the appendix, which had the calculations, didn’t have anything past high school algebra). I wasn’t the target audience, which is a little bit sad, because I’d love to read the same book written for people who already like science. His enthusiasm is truly catching, and I love it.
My favorite part of the book is when he mentions Maxwell’s equations, and that “by playing around with these four equations, … he concluded light itself had to be an electromagnetic wave.” Lewin takes exactly one paragraph to summarize what my Physics 12 professor took about ten minutes at the very end of our very last lecture. One paragraph, ten minutes, for what was for me the most exciting, most incredible, and most mind-blowing realization of my life.
If you don’t like math, or you don’t like physics, I strongly recommend you read Lewin’s book, because it really does offer some fantastic insights into the world around us. There isn’t any math or difficult physics, and its written with you in mind!
If you do like physics, I’m going to try to explain what knocked me off my feet, so to say, in that physics class.
I’ll be really honest: I don’t remember the actual math of what Prof. Mann was so kind to quickly scribble on the board, and I don’t really care. What I do remember is what it meant (arguably the more useful accomplishment):
We know that a change in electric field can induce a magnetic field. Similarly, we know that a change in magnetic fields can induce an electric field. At this point, I was thinking – can the two induce each other? Apparently, I wasn’t the first one to think like this: Maxwell had the same idea, and the mathematical abilities to do it.
When you do the math, you discover that there is exactly one speed at which the two fields induce each other: 30,000,000 m/s. Also known as the speed of light.
Great! What? So?
It had always been a mystery to me: why was the speed of light that particular speed? How did Einstein know that light would travel away from you at the same speed, even when you were traveling close to the speed of light? Why is it that so many waves (X-rays, visible light rays, infrared rays) all traveled at the exact same speed, even when they have different energies? Why is it that light not only travels millions of miles a second, but that it continues to travel for such a distance? (Everything else, it seems, is affected by resistance of some sort!) And now I know: its because the two fields are constantly inducing each other, like nature’s very own magic trick.
If you made it through that explanation, congratulations! And I’m sorry it was so very bad. But you either like science or wanted to know what was so great. Either way, you should go check out Walter Lewin’s book For the Love of Physics too, because its good fun, and full of interesting facts to share with the people around you.