Hands-On at Home
Every semester, roughly 200 students from across the university roll up their sleeves for experimental physics. The course serves not only as the introductory lab course for physics majors but fulfills a general education lab requirement for many students.
When Associate Teaching Professor David Anderson was tasked with moving the course online amid the coronavirus pandemic, his first thought was “how on earth are we going to do this?”
“Sometimes you get so involved in the minutiae of the course that you can’t see the wood for the trees,” Anderson said.
He had to step back and think about not only the learning objectives of the course but also how to adapt those objectives to these new and unprecedented circumstances. A large part of the course focuses on learning on how to analyze data and draw conclusions from experiments, something that was relatively easy to adjust to at-home instruction.
Anderson began by reworking some of the current experiments in the lab. In one experiment, students would normally use a spectroscope to measure the light emitted from hydrogen. To adapt for online instruction, Anderson took pictures of what students would have seen through the device. While they don’t get to use the device themselves, they can use the photos to learn how to make the right measurements and analyze the data they collect.
But Anderson admits that to truly meet the goals of the course, students do need some kind of hands-on work.
“With hands-on work, there’s no substitute for doing the experiment yourself — learning how to get a good sense of all of the potential issues and errors that can arise when you do an experiment and how you might go about controlling for those,” Anderson said. Experimental work also teaches students how to document their work by writing procedures, testing hypotheses and analyzing and communicating their results.
Thus, he created new experiments to capture the hands-on elements of the course where students could learn how to set up, conduct, analyze and report a scientifically rigorous experiment.
Running in the footsteps of Galileo, Anderson tasked students with analyzing the motion of objects falling over different distances to determine a precise value for acceleration due to gravity. Using their cell phone’s video camera, students can record the falling object in slow motion and go through the video’s time index to accurately measure its motion.
“Five or 10 years ago, we wouldn’t have been able to do this with any precision from home,” Anderson said.
With a little ingenuity and modern technology, “you can do high-precision experiments that meet all the goals of the course — the documentation, the rigorous analysis, the deciding if you’re prediction agrees with the theoretical model,” said Anderson.
Whether in person or online, Anderson believes the beauty of the course is learning how to design and carry out a scientifically sound experiment and examine all the elements that come with that, such as understanding experimental uncertainty, statistical significance and data analysis.
“I think we were able to transition the course online because the focus of doing these experiments is not on learning how to use the particular equipment. The course is really focused on the broader concept of the experiment itself,” said Anderson.
When all is said and done, his goal is to equip students with the analytical and practical tools to become adept scientific researchers regardless of what the experiments are or what equipment is used.
Mathematical Sciences Department Holds Virtual Poster Competition
For the 11 undergraduate students presenting their research in this year’s Mathematical Sciences Poster Competition, things were a little different. Instead of standing by their posters in the Cohon University Center and explaining them, the participants competed via Zoom.
“I’ve run the competition for several years now, and I know how much it means to our students to have an opportunity to showcase the amazing work they’ve produced,” Associate Professor Ian Tice said. “When I heard that the Meeting of the Minds was shutting down, I knew immediately that I had to step up and run our program virtually.”
Meeting of the Minds, Carnegie Mellon’s annual undergraduate research showcase, was canceled for 2020 in response to the COVID-19 pandemic.
Running a virtual competition brings new technical challenges, however, as Tice found out. To avoid internet connectivity issues, the participants recorded their poster presentations instead of giving them live. Then, on the day of the competition, the participants logged in via Zoom to answer questions from Tice and his fellow judges, associate professors Wesley Pegden and Clinton Conley.
The grand prize winner was senior Fei Peng, who presented a poster about research he did as part of a Summer Undergraduate Research Fellowship last year with Assistant Professor Florian Frick. The poster detailed his work on the question “what can you draw” with a unit-disk brush and a unit-disk eraser. Peng said he was inspired to study the topic after doodling on a website for creating custom maps.
“I liked having the competition over Zoom,” Peng said. “By doing this we enjoyed the fun without risking our lives.”
For senior Philip Lamkin, the competition was a little odd. “I’m used to being able to interact with someone while giving a presentation and judge their reactions, so missing that feedback was hard to deal with,” he said, though overall it was not a bad experience. Lamkin was one of three unranked runners-up in the competition. His poster discussed how averages of random variables behave.
“When you flip one coin, you get heads or tails, each with a 50% chance,” Lamkin explained. “But what about when you flip lots of coins? We can give a nice answer for that (the binomial distribution), but then what happens if you replace ‘coin’ with an arbitrary source of randomness?”
Tice said all things considered the competition went very smoothly, and he was glad it was able to still take place.
“We’re very happy that the poster competition was one fewer thing taken away from our students this year,” Tice said.