sexta-feira, 6 de fevereiro de 2009

8.02 Electricity and Magnetism Introduction, by Walter Lewin (transcription)

Abaixo, está a transcrição da fala introdutória do Prof. Walter Lewin para a disciplina 8.02 - Eletricidade e Magnetismo.

A transcrição de todas as outras aulas deste curso já está no site do MIT/OCW - somente essa estava faltando, então fiz essa transcrição na intenção de ajudar a tornar esse material acessível ao maior número de pessoas. Pretendo fazer a tradução de todo o material, quando tiver tempo.

Se alguém encontrar algum erro, ou quiser juntar-se a mim nesse trabalho, por favor, entre em contato pelo email: fprudente@gmail.com

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Well, 8.02 is, of course, largely about Electricity and Magnetism. And at the hart of Electricity and Magnetism are the four... the famous four equations we call them the Maxwell's Equations.

It's quite a difficult course for students, and I go out of the way to also introduce many phenomenon that they see around them, and make those phenomenon connect with Electricity and Magnetism.

For instance: lightning, I do an electrocardiogram in class, I discuss metal detectors, I discuss musical instruments, magnetic levitation, I talk about northern light, which is very relevant to Electricity and Magnetism, I spend almost the whole lecture on particle accelerators, I tell them why the sunsets are red, and why the skies are blue; I talk about rainbows, about halos, about glories... I talk about color perception, and since I do Doppler effect I also talk about Big-Bang cosmology; and then, during my very last lecture, I introduce them into my research... the research I did during my early days at MIT, when I was making x-rays observations from very high-flying balloons at altitudes of 140 to 150 thousand feet.

So, my goal is, wherever possible, to make them see "through" the equations, to make them see the "beauty" all around them and, by doing that, to make them love physics.

Well, the 8.02 course is the second course in physics, it's mandatory, its what we call a general institute requirement, either you have to take this course, or you have to take one, which is slightly higher level: 8.022.

So, it is the... it is the basis that students get during their first year, 8.01 - Newtonian Mechanics, and then 8.02 - Electricity and Magnetism; and if they go into Physics, of course, they get a lot more, but if they never go into Physics, then this is all they will ever see about physics, which is quite a lot, actually!

We evaluate the students through traditional exams, and, the lectures are given in the main lecture hall of MIT, and then the students meet, in smaller groups, with professors, we call those "recitations", which is largely problem solving.

There are many events on this course, every lecture is an event, and the students will have taken me... well... telling that, indeed, going to my lectures is an event. I'm not a very traditional lecturer, so therefore I really like to think this lecture is an event.

We do have a contest, which is very, very popular: we hand to the students a piece of wood, some copper wire, a few paper clips, and two magnets, and the goal is to make an electric motor; and they get a quote of credit depending upon how fast the motor is going, and this is really... a real happening, it's an incredible event, and some of the motors are extraordinary in their design. If you and I would try to build a motor, we'll be lucky if your motor rotates 400 revolutions per minute, but let me tell you, some students go to the 5000 revolutions per minute mark! it's really quite... quite amazing, and they really spend so much time on that... it's a wonderful event, it's really a happening!

My message to all educators is: what counts is NOT what you cover, but what counts is what you UNCOVER, and this is often forgotten! so, there is a general tendency, not everyone, but a general tendency, to run too much down the throats of the students, and overlook that that's very anti productive, because it goes one ear in, as we say in Holland, and it goes other ear out again. So what you cover is not what matters but what you uncover is what matters. And if you can somehow do it so that there are parts of the course that they will remember for the rest of their lives, that's even more important. If a student has come to my lectures on rainbows, and halos and glories, for the rest of their lives, rainbows will never be the same! and they will always think of me, when they see a rainbow and, in fact, sometimes 20 or 30 years after a lecture, they send me still pictures, and they say "professor Lewin, I saw a rainbow and I thought of you, and here is a picture!", and the interesting thing is they sometimes send me a picture which is not even a rainbow, it is a glory, but it doesn't matter... what it shows is that I have succeeded in making them love Physics, and that's my goal, and that should be the goal of every educator: to make them love Physics.

Walter Lewin, 8.02 Electricity and Magnetism (Introduction), Spring 2002. (MIT OpenCourseWare: Massachusetts Institute of Technology), available online (Accessed 06/feb/2009). License: Creative commons BY-NC-SA

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