Teaching physics

Physics has its roots in natural philosophy with Aristotle explaining natural phenomena in terms of what he called the “natural place.” According to him, an object’s motion is a result of its effort to reach its natural place. For example, why does a stone fall faster than a feather? To Aristotle, this was because the natural place of the feather is the air and the natural place of the stone is the earth. After two millennia of its reign, Aristotelian philosophy was overturned when Galileo proved using experimentation that his claim was wrong. From then on, experimentation became the basis of explaining natural phenomena in contrast to pure assumption or reason.

Today, physics has evolved. More and more branches of physics have flourished, and not only can the motion of the stone and the feather be explained, but also the motions and nature of subatomic particles, the motions of galaxies, and even the possible origin and fate of the universe. Alongside these, older branches of physics are established as part of the mainstream of learning.

However, the establishment of other fields like the mechanics of Newton, for example, has “blinded” most students to the real meaning of physics. Physics, for most of them, is finding the formula in the book and plugging the numerical values whenever there is a physics problem from a reference. “Do not look for the formulas,” I often discourage my students. “Imagine and analyze what is happening. Do not think too shallow, just like high schoolers think. Act like a scientist, or a mathematician, or a computer scientist, or a biologist,” I often find myself saying that.

But sometimes, even though the students have learned their lessons (i.e. they have learned already how to analyze and gain physical insight from imagining the situation in the problem), time comes that the analysis of the problems on their part is excruciatingly dull (most of them, if not all of them, are not conscious of this) because they are actually often routine applications of procedures mentioned in lectures or in books. That is, the book problems do little to force students to reflect seriously about new and more realistic situations that will bring out and develop their technical skills, insights, and originality.

To escape the excruciatingly dull moments and at the same time erase the widespread misconceptions about physics, I once brought to class a documentary film (from Discovery Channel) on the International Space Station (ISS), a station in outer space that was primarily installed to protect our planet from asteroids that destroyed the dinosaurs 65 million years ago. For a slightly trained non-physics major class (e.g. biology major), this would somehow be a test of persistence and intellectual stamina, again, just like the physics problems from references, because of their notion that space exploration etc. is only for astronomers, engineers or physicists, and the like. But when they viewed the detrimental physiological effects of weightlessness on the astronauts and the very exciting and numerous biology-related researches that can be conducted in outer space, their interest became evident. They became seriously attentive to what the speaker had to say.

After the show, I pointed out the importance of collaborations of different fields and the interdisciplinary learning that has been taking place through projects like ISS. Seeing that time was running out, I ended the class by saying something like this — physics needs biology, and biology needs physics: that is, fields of learning need each other. Days later, I was quite joyful because some students gave me positive feedback.

More to escaping dull times in classroom discussions, I also find time to expose them to some of the very active research fields in physics today. These researches are thrilling because even at their infancy they are already discovering things that will stun everyone! Take the case of the 20 fundamental constants in physics (e.g. the constant for the charge of the electron, the constant for the strength of gravity, the mass of the electron, etc). The strange and mind-boggling thing is, when these constants don’t have the value they have today, even only one of them (!!), we won’t have a universe as we observe it today! It seems that the 20 fundamental constants of nature are “finely tuned,” maybe, for us to exist on the surface of this planet! Amazing isn’t it?! (This “proves” that there is more to physics than equations and even if it’s a somewhat hard subject, the results are rewarding and worth it!) Sadly, only a very small percentage of our population is aware of this kind of wonder and beauty that nature is disclosing to us. 

With the present number of high school and college students, how many are those who have the misconception of physics being a plug-into-that-equation and hard subject? And how many are those who see the big picture? The discrepancy is large. It’s a continuing hope, therefore, that the naive and wrong notions about physics will be overturned just as Aristotelian philosophy was overturned by the experimentations of Galileo, that teaching physics will no longer be constricted by wrong notions. If this will happen, a new perspective will spring about physics and consequently, science in general, and we will be on our way to make great scientific advances like never before.

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This article was originally published in Ti Similla (now with some revisions), the official newsletter of the academic staff of UP Baguio.

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Melchor A. Cupatan is an instructor of physics at the University of the Philippines Baguio. He attended his undergraduate study at the University of the Philippines Baguio. He is currently teaching modern physics and statistical physics to physics majors, and fundamental and general laboratory to math and biology majors, respectively, after graduating in the summer of 2008. His interest is more on theory — because of its beauty and elegance — than experiment. He is planning to pursue his MS with either cosmology or particle physics as his field of specialization. E-mail him at [email protected].