Tuesday, June 04, 2019

Quantum Physics in Secondary School? How Some Teachers Capture Student Interest Early

For many people, the phrase “quantum physics” evokes images of science fiction-like technology, a vaguely puzzled sensation, or perhaps just a shudder. Yet for a growing number of secondary school teachers worldwide and their teenage students, quantum physics represents a gateway to a lifelong love of science.

Kirsten Stadermann is one such teacher. Although she originally intended to make a career of researching laser physics, she “accidentally” started teaching in Holland when a local school lost a teacher unexpectedly.

“It was such a great experience,” she recalls of her first few months on the job. “At the school I was smiling all day long… and I thought, well, that’s what I want to do.”

Stadermann started off scouring the literature for mention of state and national standards that mentioned one or more topics generally regarded as modern or quantum physics*. Although she faced difficulties in finding readily accessible documents, which ultimately limited her study to mostly European countries, she analyzed the curricula of 15 countries that mention quantum physics—five more than had been previously studied. In addition, some of the countries (Germany, for example) set their educational standards on a state-by-state basis, so in total, she reviewed 23 different curriculum documents.
She noticed immediately that almost all the countries approach quantum physics as an elective or advanced option for students already studying physics—about 5%-20% of the overall population of 17- to 19-year-olds. She was surprised to find, however, that Einsteinian physics is a central component of the standard physics curriculum in Australia and the German state of Bavaria for students as young as 14 or 15. Despite some teachers’ concerns that younger students would be hopelessly befuddled by such complex topics, research shows that they are actually quite capable of grasping the key concepts. In fact, the mind-bending aspect of physics served to increase student interest in the subject—particularly among girls.
This meshes with Stadermann’s own experience in the classroom. As she explains, high schoolers don’t have the foundation in math that is required for quantum calculations, so teachers are forced to discuss the concepts in qualitative terms. This frequently leads to broader speculations on the philosophical implications as students grapple with such seemingly impossible ideas as wave-particle duality or the Heisenberg uncertainty principle.

Stadermann recalls, “[At first] I was a little bit afraid that in the end they couldn’t pass the exams… but the funny part is that these classes—where we had these discussions—did much better than the other classes.”

Artist's rendering of quantum entanglement

One of the biggest challenges faced by physics teachers lies in the fact that quantum physics is anything but straightforward. Indeed, it’s the very fact that there is no one “right” interpretation that many students are excited by the subject. “It’s very important to show them…that everybody understands that nobody understands it,” she says. Not only does this assuage the students’ anxieties when faced with difficult concepts, it illustrates for the students the very nature of science itself.
Scientific understanding is, after all, anything but uniform and static. For centuries, individuals have grappled with confusing observations, argued adamantly amongst themselves, and worked together to synthesize their many insights into a set of overarching theories. And as students discuss the merits and implications of various models, isn’t that what they experience on a smaller scale? Stadermann hopes that by engaging more fully with the nature of science in the classroom, students will be less susceptible to the distrust that all too often follows scientists. In particular, she mentions the fact that many people are wary of climate scientists because of the disagreements that occasionally erupt between them. “[My students] can understand that that’s normal, not a bad thing,” she says optimistically.
Naturally, there are reasons that quantum physics hasn’t been adopted as standard curriculum by droves of countries. For one, every hour spent on quantum physics is one hour that isn’t spent on another topic. For another, quantum physics doesn’t lend itself to the inexpensive and simple lab experiments high school teachers usually rely on for concrete experience. Finally, how can you test a topic where there are no right answers?
Stadermann readily agrees that it is difficult to choose a topic to abandon in favor of quantum physics. In Holland, the school board caused a controversy when it elected to cut optics, a subject critical to the understanding of everything from glasses to telescopes. That doesn’t necessarily mean that the students understand less of the world, though. In fact, they can develop a greater appreciation of modern electronics and explore cutting-edge technologies like quantum computers—arguably even more important to a young person preparing for a 21st-century career.
While it is also true that quantum physics doesn’t lend itself easily to lab experiments, students aren’t automatically devoid of the laboratory experience. Stadermann and countless other teachers have found the PhET simulations put out by the University of Colorado to be invaluable. These free applications can run on nearly any computer—no expensive lab equipment needed—and provide the students with a way to tweak and test to their hearts’ content. Stadermann cautions only that the students must be encouraged to form their own explanations and discuss amongst themselves for the simulations to be truly useful.

“Talking about interpretations from Bohr and Einstein doesn’t really help if the students are not allowed to think themselves,” she warns.

A PhET simulation designed to teach students about the photoelectric effect. Credit: PhET

The question of testing quantum physics in secondary school is more difficult. Stadermann has used both multiple-choice questions and in-depth oral examinations to study the effectiveness of her teaching, and they tell drastically different stories. In the multiple-choice tests, her students performed poorly overall, averaging around 7 correct answers out of 20. When she actually spoke with them, though, it soon became clear that they had a broad understanding ranging over a variety of interpretations—and what’s more, they enjoyed delving into deep philosophical questions. Even more importantly in her mind, they showed a good comprehension of the nature of science. “The question is, what are we actually testing with the multiple choice tests?” she asks.

Teachers of many other subjects, like literature, already rely on open-ended or essay-based exam questions for this very reason. “But physics teachers always want a yes and no answer so the whole culture of physics is different,” Stadermann says. In this sense, physics teachers are used to comparing their classes’ completed exams against an answer key, and the habit dies hard.

Even so, Stadermann believes there is value in teaching quantum physics even if it is not always satisfactorily tested in final exams—and that’s the benefit it brings to the students. They learn to cope with competing perspectives and enjoy the philosophical and technological implications of quantum physics. Perhaps most telling is the fact that she typically has five students per year who go on to study physics, when most classes produce just one. It’s not the study of projectile motion that captures her students’ interest—it’s the parallel universes, quantum tunneling, and semiconductors that they simply can’t get enough of.

The math can come later.

–Eleanor Hooke

*The complete list of topics considered by this study are as follows:

Blackbody radiation
Bohr atomic model
Discrete energy levels (line spectra)
Interactions between light and matter
Wave-particle duality/complementarity
Matter waves, quantitative (de Broglie)
Technical applications
Heisenberg’s uncertainty principle
Probabilistic/statistical predictions
Philosophical consequences/interpretations
One dimensional model/potential well
Atomic orbital model
Exclusion principle/periodic table
Schrödinger equation
Calculations of detection probability

1 comment:

  1. Physics is one of the most common science subjects taken in Singapore, with most students taking either pure physics or combined sciences (physics/chemistry). Yet, for those who are new to the subject such as secondary three students, learning about mechanics, light waves, heat radiation, electromagnetism and the structure of atoms can be a little daunting.Quantum physics is one of the most interesting topic to know more.