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QUANTUM physics – known to practitioners as quantum mechanics – is a subject that physicists learn in a rather peculiar way. We all learn to calculate using its mathematical framework, but that doesn’t mean we can really explain what it all means. If we go far enough in our education, we get the opportunity to see just how accurately these calculations match experimental results, so we learn to trust that they are correctly describing reality.

But how can a cat be both alive and dead inside a box before we look at it? We can do calculations that are consistent with this interpretation of the equations, but what can that possibly mean, physically? Quantum mechanics is filled with what we might consider surreal: it is hard for us to make rational sense of it, yet the mathematics implied by our experimental results commands us to draw certain conclusions.

One classic experimental result is that light behaves like both a particle and a wave. Despite being most famous for special relativity and general relativity, Albert Einstein actually won the 1921 Nobel prize for his contribution to understanding this wave-particle duality, which became a cornerstone of quantum mechanical theory. Einstein’s work combined with that of Max Planck to show that light came in quanta: lichtquanten, or discrete packets of energy known as photons. These photons acted like particles, but also acted like waves.

The most accessible way to explain how this is possible is using the famed double-slit experiment, something students can now do in their undergraduate lab course. Lasers are shot at a plate with parallel slits. The pattern that forms on the wall behind the slits is the kind we would expect to see with a wave. But when observed closely, the pattern is comprised of discrete, individual absorption points: what we would expect from something acting like a particle, not a wave. Light, it turns out, is both.

A century ago, a PhD student named Louis de Broglie dramatically broadened the quantum revolution that was under way. In 1923, de Broglie published a series of articles putting forward the hypothesis that wave-particle duality was a property of all matter, not just light. He wrote down an equation that connected a particle’s mass and velocity with a wavelength, the distance that a wave repeats over. This became the foundation of his 1924 PhD dissertation. Three years later, confirmed that electrons behaved in a manner consistent with de Broglie’s claims. In 1929, de Broglie won a Nobel prize for his contribution to physical knowledge.

We teach de Broglie’s equation – and Einstein’s precursor to it – multiple times in our curriculum at the University of New Hampshire. Students see it in a modern physics course, a baby steps-style introduction to advanced concepts in physics. They then see it again in thermodynamics and in their introduction to quantum course. I also teach it in my stellar astrophysics course. This is all to say that a physicist is expected to be very familiar with wave-particle duality and have facility with its mathematical form.

Something we don’t teach in classes is that, actually, there are alternative interpretations to wave-particle duality, including one advanced by de Broglie himself and fully developed later by physicist David Bohm. In this picture, a wave and particle simultaneously exist. There are still other ideas where you can explain the data entirely by using a wave model, with no particle necessary.

I came of age thinking this was a problem for philosophers, not physicists. Then I turned into a physicist who also did philosophy, and that boundary seemed increasingly strange to me. My interest in how race, gender and class shape outcomes in physics led me to question why we exclude the conceptual challenges of quantum mechanics from the classroom. The generous explanation is that we only have so much time with students and we have to make difficult choices about what to teach.

But it is also the case that students come to our classrooms in part because they are enthralled by the strangeness of physical theories like quantum mechanics. Unfortunately, from an economic perspective, there is a lot to be gained by knowing how to calculate and ultimately engineer with these ideas, even if we struggle to make conceptual sense of them. There are no obvious physical applications to trying to understand the conceptual heart of the issue.

I completely understand the logic at work here, but it is also so obviously limiting. Students are cheated out of an opportunity to think deeply about the surprising ways of the physical world at the smallest scales, and that is itself an educational failure.

Chanda Prescod-Weinstein is an assistant professor of physics and astronomy, and a core faculty member in women’s studies at the University of New Hampshire. Her research in theoretical physics focuses on cosmology, neutron stars and particles beyond the standard model.