Science Teachers, Be Honest About What Science Still Can't Explain
"If you figure that one out, I want a picture with your Nobel Prize."
If asked, most people will claim they know how a toilet works. But when asked to explain, most simply can't. Yale psychologists Leonid Rozenblit and Frank Keil called this the "illusion of explanatory depth." A similar failure of intuition leads people to overestimate how fully science can explain our universe. To inspire the next generation of scientists, science teachers must reverse this misconception by making it clear to students that despite all we’ve learned, our universe remains ever mysterious.
Throughout my years as a student I subconsciously formed a conclusion about scientific discovery that can be stated in just three words: It already happened. I believed that the big questions—What is matter? What are living things made from? Why do things fall downwards?—had already been answered and that most of 21st century science is concerned with negotiating the marginal, idiosyncratic details.
These feelings didn't deter me from science altogether because my interest was largely rooted in a desire to solve practical problems, not to explore the unknown. If nitpicking over tiny details—the leftovers of real discovery—would lead to cures for diseases, then sign me up. But many students are driven to science by curiosity, not pragmatism. These are the students whom science risks losing to other careers.
It wasn't until I started studying molecular biology during my fourth year of college that I understood how much has not yet been discovered. As my classes became more advanced, my professors increasingly answered students' in-class questions with "That is a total a mystery" or "If you figure that one out, I want a picture with your Nobel Prize."
It is not self-evident that there are important aspects of the universe that humankind doesn't yet understand. For children to realize this, someone must tell them. Almost all unanswered questions, to an expert, are questions that have not yet been asked to a lay person. The average 5th grader has no way of independently discovering that immunologists do not fully understand how memory T-cells are generated, because most 5th graders do not know what memory T-cells are.
A child might ask his parent or teacher, "Why do we need sleep?" He would be asking a question that truly does not have a good answer yet. But, if the child is given even a partial answer—one that even the child may find unsatisfying—the effect would be completely different than if he were told, "Nobody really knows yet, but people are very interested in learning!" The mere knowledge that someone on Earth thinks they have the right answer can be enough to deflate the child’s curiosity.
In the age of the internet, the mysteriousness of the universe is less obvious than ever. Google essentially puts the entirety of human knowledge at one's fingertips. Internet search engines perpetuate the illusion that we already know everything by supplying the user with "answers" to nearly every question, even if those answers are mere guesses at best. Try Googling "What is the meaning of life?" You will have to wade through many genuine attempts to answer this question before finding a single, "Who knows?" In a pool of answers to an unanswerable question, the most honest answer, "nobody knows," appears to be just another guess. It is precisely because of the apparent expanse of human knowledge that children desperately need to be taught about its limits.
Educators, policymakers, and textbook writers can all play a part, by embracing the importance of actively teaching what we don't know. At the same time, we must teach students how we are so sure of these gaps in our knowledge. What observations tell us there's more to the story? We must also communicate the reality of unknown-unknowns to students—that the answers to many of the questions we have will likely be found through learning about things that we currently don't even know exist.
Students should know that the material they are learning today can all be subjected to radical reinterpretation—just as the geocentric model that placed Earth at the center of the cosmos was centuries ago. For instance, we teach students about sleep, dark matter, and the chemical origins of life, all of which are still largely unsolved mysteries. Teaching students about paradigm shifts of the past—as in what happened to geocentrism—is not the same as teaching them there might be paradigm shifts yet to come. For students, learning that there were mysteries does not necessarily translate to understanding that there are still mysteries for them to unravel.
Ultimately, to make the universe feel exciting, an emphasis on the unknown must be integrated into science curricula. We need to test our students on their understanding of the gaps in our collective scientific knowledge and write our textbooks with this intent in mind. Teachers must resist giving partial answers to questions from students in situations when an affirmative "nobody knows (yet)" would be more appropriate—and inspirational. Students don't need to memorize every specific incarnation of scientific ignorance, but they should understand that the universe remains ever mysterious, and they were not born too late to explore it.