letter to the editor
But at What Cost?
To the Editor:
I wish to express some remarks about “Studying Collisions: Social Justice in Physics,” featured in the March/April 2022 issue of this publication.
The authors raise questions about what diversity, representation, and equity could look like in a science classroom, and use an example physics lesson to demonstrate their model for such practices in the classroom. I enthusiastically agree that discussions of diversity and historical inequities in the sciences must be acknowledged at appropriate times in the course of teaching fundamental science concepts. We can and should acknowledge that the history of scientiﬁc inquiry and discovery is replete with the social realities of the times of those discoveries. We have made strides in correcting these prejudicial views, though we should continue to acknowledge that there are still barriers to entry that result in the makeup of our classes not reﬂecting a parity with the communities that we serve.
With that said, I believe the approach taken to diversity and inclusion in this lesson could have been greatly improved. I believe good science teaching practice must begin, end, and be wholly composed of good science. I also believe that good engineering practices can only be developed once students have a solid foundation of knowledge from which to draw in order to design solutions.
In order to meet these standards, I believe students should learn: proper methods for making measurements, including qualifying and quantifying uncertainties; important conceptual frameworks that form the foundation of inquiry in our subjects; and how the analysis of data from experiments can develop, support, or refute models of the world in which we live. Once students have demonstrated that they have learned a set of skills and concepts well enough, they should be challenged to design a solution to a problem that demonstrates both this understanding and the ability to apply this knowledge in an appropriate way.
Unfortunately, too much of science education does not ﬁt this model. How many of our classes actually wrestle with the uncertain nature of measurements, in a quantitative or qualitative way? How many of our experimental results are reduced to “explaining error,” when we should be teaching students to have conﬁdence in the measurements they conducted, and explain deﬁciencies in their modeling, instead? And what of “engineering”—the “engineering” component of many science activities at an elementary or high school level simply does not match what engineers actually do. Engineers do not guess-and-check by throwing together prototypes out of whatever is lying around their laboratory without an understanding of how the materials they are using will behave. To do so would be costly and wasteful to any engineering ﬁrm. We do ourselves and our students a disservice when we reduce engineering processes to guess-and-check methods, and guess-and-check is the only process we make available to students if they do not have a conceptual background in the actual science knowledge, ﬁrst.
With the particular lesson given in this article, it is not clear to me whether the students in the class actually understood all of the critical aspects of the relevant physics before proceeding to designing their egg drop device. The authors cite the relevant NGSS standard (HS-PS2-3) as being about “minimizing the force on a macroscopic object during a collision.” The article describes how the authors engaged in a series of discussions with their students, centering on: discussion of inequities (such as in the development of PPE); representation of traditionally-underrepresented groups in natural science disciplines; and so on. They explain that these discussions happened before and during a physics lesson (an egg drop activity). The authors go to great lengths (thirteen paragraphs, at least) to describe how they implemented these conversations before ﬁnally devoting two paragraphs to the actual physics content of the lesson.
As any competent physics teacher should know, the impulse–momentum theorem is what will be applicable in an egg drop activity. The momentum change at impact of any egg dropped from a given height will always be the same, but the time of collision is what will determine the force that the egg experiences, because the impulse-momentum theorem is given by: F → ∆t = ∆ → p. The simulation the authors cite can be used to extract some data to develop this critical conceptual component, but in my opinion, the simulation chosen does not make this critical concept as explicit as it could, especially given that other examples do make this aspect of the problem explicit (Physics Classroom, Physics Aviary, JavaLab, or even one of CK12’s other simulations; see Online Connections), and are just as freely-accessible and easily-found.
There is no indication given that either teacher-led instruction or student-derived inquiry, discussion, or conclusions focused on the time of impact as a determining factor for the force experienced during the impact. Instead, the article focuses only on the diversity of design teams in a crash test dummy article during the relevant conceptual discussions, which is not cited in their references.
In my view, the diversity and social justice aspects of the discussion for this lesson would ﬁt much better at the end of the lesson, not as the introduction. I believe this because only after students have developed their fundamental conceptual frameworks can those more advanced discussions about the design of PPE be made more relevant to the ﬁeld of physics, the phenomenon of collisions, or whatever is relevant to the science classroom. For example: one group of students mentioned offhand that their egg represented a pregnant person, but the authors do not elaborate about how any aspects of that group’s design incorporated the discussion of equity or social justice by modifying their design to accommodate a pregnant person differently. This is an interesting question to consider, because if a lap and shoulder belt is not designed to comfortably or safely slow both a pregnant person and their unborn child to rest, then there could be shearing forces exerted on the pregnant person’s internal organs, among other considerations like pressure at points of contact with the safety belt.
Having these more extended discussions—grounded in the actual physics content of stretching, compression, or shearing forces as applied to this context—could serve two purposes at once. First, these conversations could continue to enhance students’ physical understanding of the world around them. And second, students could see how the inclusion of other perspectives is valuable not just for representation’s own sake—tokenism—but for practical purposes. In this particular case, potentially life-saving applications: the design of safety belts in vehicles.
But how many introductory physics classes focus on concepts like stress, strain, or shearing forces? My bet would be nearly zero, especially in the framework of Next Generation Science Standards. The NGSS framework focuses on the Big Ideas of mechanics and electromagnetism, and not on more advanced, particular concepts in each. Without being able to quantify or qualify these forces in any way through the use of models, discussion of this problem is no better than students writing “human error” to explain why their predictions do not agree with experiment.
It is for all of these reasons that I felt compelled to write these remarks in response to this article. The article’s introduction stated, “The focus of this article is not on the physics content...” But I must criticize this lesson particularly because we, as science teachers, are primarily responsible for the science content presented in our lessons. Based on what was presented in the article as both physics content and the attempted infusion of social justice issues in this lesson, I see two ways of interpreting the design of the lesson as a whole. One possibility is that there was a substantial amount of conceptual development that simply was not mentioned in the two paragraphs devoted to physics content. The authors could have been so intensely focused on including elements of diversity and social justice in both the design of their lesson and of their narrative to us that they made an oversight and simply did not cite the correct physical equations and concepts. These are concepts that students should have been very familiar with and utilizing in the design of their device, and concepts that students should have learned before a physically-grounded discussion of diversity and equity in the context of PPE and design teams.
The other possibility is that, owing to the academic backgrounds of the authors (biology and geology, not physics), the core course concepts were not developed adequately before undertaking an application project that required students to rely on those core concepts, and extend those concepts further for diverse populations.
The latter possibility is symbolic of a systemic problem in the realm of physics education. Surveys by the American Institute of Physics have shown that as little as half of American high school students take any class at all in physics (Chu and White 2021). For those students, surveys have shown that less than 40% of physics teachers actually have an academic background in physics or engineering (Rosengrant et al. 2014). Combining these pieces of data means that less than a third of all American high school students are being taught physics—a core discipline in science—by someone who formally prepared to teach physics. Or, to put it another way: most American high school students either are not being taught physics by subject-area experts, or are not being taught physics at all. I think that this issue needs to be solved at least in parallel with how to incorporate more robust discussions of diversity and inclusion in our science lessons.
If the retort to all of my remarks above is simply that more time should be spent on delving into the important issues of diversity, social justice, and inclusion in the science classroom, I can only agree, and state that I think those discussions are best served after core concepts are developed, not while basic conceptual development is in motion. If the retort is instead that more advanced physics concepts should be discussed in order to have those more robust discussions of diversity and social justice that are grounded both in good values and in good science pedagogy, I can once again only agree, but reply that those concepts are not in the NGSS framework, and that my time in the classroom is limited.
What I know to be true is this: in the science classroom, we deal with nature as nature really exists. We operate under the assumption that all the physical laws of the universe operate regardless of who the observer is. The law of momentum conservation works regardless of whether the occupants of vehicles in a car crash are of Eurasian, African, or American descent; feel attraction to people of the same or different gender identities; are socioeconomically fortunate, or not. That objective truth is the core conceptual framework that I wish to impart to all my students as they become young adults capable of thinking for themselves. Like all of my colleagues, I must make careful decisions about what concepts to discuss, when, and in what manner.
I can only wish I had the time needed to both explore the universe and solve all social problems through my science class.
Physics Simulation—Egg Drop: https://www.physicsclassroom.com/Physics-Interactives/Momentum-and-Collisions/Egg-Drop/Egg-Drop-Interactive
CK-12 Education Series—Crash Test Dummy: https://interactives.ck12.org/simulations/physics/crash-test-dummy/app/index.html
I want to thank the author, Wayne Ernst, for his thoughtful, thorough letter to the editor (the authors were contacted to provide a reply to the letter but no reply was received.)
Ernst is eloquent with his remarks and does point to the paucity of physics teachers (and all licensed science teachers, as a whole) in our society. I will only have six future science teachers in my methods courses this next academic year, and I am not alone. There is a national trend of college students not pursuing education as a career choice.
For me, Ernst’s comments are profound, but the most pressing issue is the lack of individuals pursuing a career in science education. Will the pendulum swing so that teaching is perceived as a viable profession? Some of my graduating teacher candidates are now being offered signing bonuses to teach physics, in particular, in rural schools. Yes, the science teaching situation is that dire. Also, principals insist on the science teaching applicants having an Integrated Science degree meaning they can teach ANY of the science disciplines. Tell me, how can an undergraduate with just one year of physics coursework be prepared to teach a higher level physics course, AP physics course, or honors physics? Yet this is what is happening all over the country.
Our society needs knowledgeable, licensed science teachers, but the movement is trending towards sending anyone into the classroom with minimum professional development to teach our children. Finding knowledgeable physics experts to teach physics is not happening, and won’t happen in the foreseeable future given all the controversies facing educators today, such as mandating guns for teachers, more non-education individuals making critical decisions regarding the profession, and the plethora of standardized tests that foster a distaste for science more than a passion for it.
In terms of what Ernst sees as a lack of physics rigor in the article, we are now seeing students enter physics courses without the math skills, the numerical prowess to handle the “usual” physics formulas, and to really comprehend the concepts behind the formulas. The students want to “plug and chug” and be done with the assignment. Some teachers just want to “cover” the content rather than “uncover” the content with the students, which takes much longer. Feeling pressed for time, the teachers move along at a rapid pace even knowing the NGSS is striving for depth over breadth of content.
NGSS is phenomena-based and encourages a classroom where students pose questions of interest or be prompted with an investigatory question or situation. Ernst suggests that students begin with learning the skills, have the numerical prowess, and understanding of the concepts prior to investigating phenomena. The science education literature is replete with evidence that students must first be engaged prior to learning anything.
I do agree with Ernst that the engineering projects in many schools are done without the students truly understanding the science behind the project; however, we focus on content so much that students leave our classrooms without experiencing the science and engineering processes at a bare minimum. The article provides students with the opportunity to experience phenomena in a way that is engaging and can be further explored in an equitable manner.
Finally, I want to reiterate that I applaud Ernst for his thought-provoking, erudite letter that promotes discussion. I do welcome letters that address his thoughts as well as mine.
You, as readers, make the journal the important one that it is and I want to take this opportunity to thank each of you for making this happen.
Ann Haley MacKenzie
Editor, The Science Teacher
Chu, R., and S. White. 2021. High School Physics Overview. American Institute of Physics. https://www.aip.org/statistics/reports/high-school-physics-overview-19
Rosengrant, D., L. Watanabe, G. Rushton, and H. Ray. 2014. Recent Demographics of Physics Teachers From Schools and Staffing Survey (SASS). Poster presented at AAPT Summer Meeting. https://www.aapt.org/docdirectory/meetingpresentations/SM14/Rosengrant-AAPT%202014%20summer%20poster%20final.pdf