Teaching physics with phones: A game changer?

Physics Toolbox began after Vieyra took 300 high schoolers on a trip to an amusement park to teach some fun physics. The motions on roller coasters and other rides illustrate phenomena such as free fall and circular motion and the forces they exert on the human body. “We didn’t have enough lab instruments for them to strap to themselves, so my husband made an app for me,” she says. “We started with a g-force monitor and a linear accelerator and just kept adding.” With support from NSF, she and colleagues in 2019 added a feature called Magna AR, a magnetometer with augmented reality that visualizes magnetic fields in 3D (see photo on page 24). In 2022 they added a tool that uses lidar (light detection and ranging) for motion experiments. The tool is available for use only on certain models of iPhones and iPads.

“What came as a surprise to me as a designer was that we created this for high school, yet our tools have been picked up so much at the university level and are used for non-teaching-related research,” says Vieyra, who is now at the Office of Academic and Learning Innovation at the University of Colorado Boulder.

No statistics are available on the numbers of teachers and professors who are using smartphones in class. Physics Toolbox has been downloaded 2 million times and averages 24 000 downloads per month. Rakestraw estimates that several hundred high schools and dozens of colleges are now using Physics with Phones experiments. Since it was released in 2020, about 35 000 users have downloaded the curriculum.

Ann-Marie Pendrill, a retired high school physics teacher in Sweden, volunteered to survey the country’s high school teachers for Physics Today. Of the 127 Swedish physics teachers who responded, 27% said they had used phyphox or Physics Toolbox in their classes, while 28% had never used smartphones in their classes at all. Others reported using single smartphone sensors and apps for such things as producing slow-motion videos or measuring audio levels.

“People tend to use what they have been using, and a lot of people don’t know” about the teaching apps, Pendrill says.

Arturo Martí, a professor at the University of the Republic in Uruguay, estimates that 10–20% of secondary school students in his country are being taught physics using smartphones. He says that when he tries to educate teachers about the phones’ capabilities, “they will say, ‘This is very interesting and we can use the tools.’ But most of the time, they don’t do that.” Many complain that they don’t have enough phones for their classes.

Nicole Murawski, a former high school physics teacher in Michigan who more recently has worked to familiarize teachers with Physics Toolbox, surveyed US physics teachers on X, formerly Twitter, also at Physics Today’s request. Of the 45 responses she received, half reported using unspecified smartphone apps once or twice a year. Another 20% said that they used them up to twice a month, and 9% reported using them one or two times a week. But 22% said they didn’t use them at all.

Smartphone sensors, many of which are embedded on a single microchip, weren’t designed with physics teaching in mind, but they offer remarkable precision. Barometers, for example, can measure air density to three significant figures, says Rakestraw. That enables an exercise app to calculate the number of steps a user has climbed, and it also lets students see how air pressure changes during an elevator ride.

Smartphone accelerometers were sensitive enough to produce a seismocardiogram—a recording of the body vibrations produced by heartbeats—that detected Rakestraw’s previously undiagnosed mitral valve prolapse. The physicians treating him were taken aback by the accuracy of the reading, he says, which was confirmed with an electrocardiogram. The Physics with Phones heartbeat experiment was particularly exciting to students in Elissa Levy’s high school physics class at Thomas Jefferson High School for Science and Technology in northern Virginia; Levy says she has fallen “hook, line, and sinker” for Physics with Phones.

“If you have an accelerometer in the classroom, you have to import the data to some program, and everybody has to then analyze it,” says Levy. With smartphone apps, “you just press a button, slide your phone down a ramp, and there’s your graph to analyze.” The data can be exported to a spreadsheet for analysis, which gives students the opportunity to brush up on their spreadsheet skills.

Using cell phones, schools and community colleges can access laboratory equipment that historically has been affordable only for wealthier schools. Many schools don’t have any lab equipment at all, says Vieyra, but even well-equipped schools are unlikely to have some instruments, like gyroscopes, found on phones. Rakestraw notes that all the experiments in the Physics with Phones handbook can be done with only a handful of supporting items—string, rubber bands, golf balls, and such—none costing more than $1.

“Our students are less well-off than those going to Princeton, but everyone has a cell phone,” says Douglas Singleton, who teaches physics at Fresno State, which is part of the California State University system. Lab equipment can be expensive; plastic collision cars, for example, can cost $150, he says. “If our students have a device in hand that takes better data and can be applied to a wide range of things, then let’s go with that.” He adds that students seem more engaged in learning with their phones. “I’ve come across students after labs, and they still have phyphox on their phones and are playing around with it. That’s great.”

The physics faculty at Fresno State is in the process of converting some of the 12 lab sections in the introductory course to Physics with Phones. “The material Rakestraw has for any given lab is enormous, so we have to pare it down to fit into the three hours we have for student labs,” Singleton says.

Those educators who are enthusiastic about smartphones say they don’t plan to use them for all their labs. Rakestraw says he wouldn’t expect them to. “Nobody develops a complete high school curriculum for physics, because no physics teachers want that. They are more independent; they all have different things they want to emphasize,” he says.

Duke University professor Berndt Mueller sees Physics with Phones as a supplement to the well-equipped labs of research universities. He has adapted several of his labs to phones in his introductory course. “In the spirit of new insights into pedagogy, we try to empower students to explore things on their own,” he says. Rather than “following a cookie recipe” using university-provided equipment, students are able to explore on their own with phones. “This fits well into how we feel physics should be taught,” he says. Still, it won’t replace all the labs in his course. “Obviously, specialized equipment has advantages. And supervised experiments also have advantages. You get to the end quicker than if you do it on your own.”

“There are settings in which this is a game changer,” Mueller says. “It allows students in any environment to do experiments, and they have the instruments with them all the time.”

Martí, a prolific author of papers on smartphone physics teaching, says he uses phones in 20–25% of his lab courses and isn’t likely to increase that percentage. He says he will continue to use dedicated instruments for teaching other labs.

The available information on how high school students respond to smartphone physics teaching methods is largely anecdotal. Levy says her students “think it’s awesome. They have it in the palm of their hand, and they can all take data. There’s a lot of direct activity you can get when you don’t have to share one device.”

A 2018 study by Katrin Hochberg of the Technical University of Kaiserslautern in Germany and colleagues found that high school students who were less interested in an experiment involving pendulums at the beginning of the study profited from the implementation of cellphone teaching. A 2022 paper by E. A. Maldonado and colleagues at the Francisco de Paula Santander University in Colombia found smartphone use in high school experiments on free-fall movement led to increased student participation and motivation.

In conference proceedings published last year, Vieyras and colleagues compared the achievement and enjoyment levels of undergraduates who learned about motion using Physics Toolbox’s lidar component with those of students who used commercial lab hardware. Vieyra says the results showed that students “get way more excited when they can use their own devices or some device assigned to them.”

Yet Vieyra is reluctant to claim that smartphones will improve student performance. “It’s not just technology; it’s the pedagogical approach,” Vieyra says. “Comparing a traditional lecture-based teacher and one who engages students in inquiry, you will always see better learning, whether the active learning uses technology or not.”

Jay Nolt, a Duke premed junior enrolled in Mueller’s class, says she thought a Physics with Phones activity on magnetic fields was one of the best labs in the course. “I thought it was a lot more engaging, and I talked with my teammates more than I did in regular labs,” she says. “We were arguing about the theory, and I think I learned a lot more deeply.”

But Nolt, who professes she loves physics, thinks she could be an outlier among her classmates, all of whom are taking the course as a premed requirement. Many weren’t happy with the additional time the smartphone experiment required, she says. A second experiment using phones took less time, and she didn’t hear similar complaints from her classmates.