Of all the classes to adapt for remote learning, a physics lab might seem among the most difficult considering that its purpose is to provide students hands-on experience with the tools and techniques of a real lab. But even before the COVID-19 pandemic arrived and caused classes to go online, Caltech senior physics lab manager Eric Black had a plan in hand that would allow his students to learn from home.
Black had found himself frustrated with the long-standing reliance on "canned experiments" in physics labs. These are exercises in which students replicate a classic physics demonstration with a known outcome, such as the oil drop experiment by Caltech co-founder Robert Millikan that measures the charge of the electron. "If they're only redoing the oil drop experiment, well, that makes them feel enlightened and educated," he says, "but they're clueless in an actual research environment."
Over the past several years, Black has tweaked the structure of the courses, keeping some of the canned experiments while training students on newer tools and skills necessary to work in a modern physics lab. He had planned to introduce LabVIEW, a software platform and programming language that is widely used for interacting with experimental hardware through a computer and for automating measurements. When Caltech moved its classes entirely online in 2020 because of the pandemic, Black realized LabVIEW could help him construct a remote-friendly course with the help of the Innovation in Education fund from the Center for Teaching, Learning, and Outreach (CTLO).
A friend of Black's who teaches at Reed College had written a textbook on LabVIEW that became the foundation of the remote lab. The physics department's COVID Teaching Fund covered the licensing fee so each student could install LabVIEW on their home computer. The funding also allowed Black to send each student a data acquisition device, which they returned at the end of the term so they could be used again. This is essentially a small USB tool that plugs into a laptop and features screw terminal inputs, allowing the user to attach bare wires and thereby feed signals into the computer.
Black had his students acquire a simple wire stripper and a cheap audio cable, such as the kind one might find on a set of headphones. The students cut into the wires and connected them to the data device. Once the system was set up, they could play any kind of sound, and the data device would capture the audio signal, which the students measured and manipulated in a variety of experiments. In this way, he says, the remote course gave students some experience working with their hands as well as working knowledge of the software.
"Now," he says, "if they walk into a lab next year and the professor says, ‘You hotshot first-year graduate student from Caltech, I know you're good at doing problem sets, but what can you do?' They can say, ‘I can program in LabVIEW.'"
The move to virtual learning was not entirely smooth. Black began his first remote labs with standard Zoom lectures and meetings but found that trying to teach a lab this way was not working for him or his students. So he moved the physics labs to an asynchronous model in which students submitted completed LabVIEW files via Caltech's Canvas program and used tools like Zoom sparingly, mostly for one-on-one meetings.
With several terms of teaching LabVIEW remotely under his belt, Black is ready to bring the experience back to the lab when students return to campus, which is planned for the fall term. He hopes to expose future students to Experimental Physics and Industrial Controls Software (EPICS), a much more sophisticated platform than LabVIEW that is used in major physics undertakings such as the MIT/Caltech collaboration LIGO, the Laser Interferometer Gravitational-wave Observatory. LabVIEW trains students to consider problems such as what sampling rate is needed or what resolution they require from the analog-to-digital converter.
"You have to start with these questions whether you are building a hundred-dollar tabletop experiment run in LabVIEW or a hundred-million-dollar project," Black says. "We teach our students to ask these questions and to consider fundamental issues so they will be able to contribute to projects of any scale."
This is part of a continuing series about innovative ways the Caltech community has approached remote teaching and learning during the COVID-19 pandemic, aided by the Center for Teaching, Learning, and Outreach (CTLO) and Academic Media Technologies.
"Caltech faculty, instructors, TAs, and students have shown tremendous flexibility as they adapted our unique educational experiences to online formats," says CTLO director Cassandra Horii. "The transition to remote teaching and learning has taught us a lot about overcoming the challenges involved, from using the technology, to creating meaningful interaction and collaboration, to aligning schedules across time zones. Caltech is building a repertoire of effective approaches, which can only enhance our flexibility."