Introduction

The physics curricula worldwide are split into lectures and laboratory experiments. Over the course of undergraduate and graduate programs, lectures cover a sequential series of courses and help students build an arsenal of sophisticated analytical tools to understand the world around them. The complimentary experiments, which are an essential part of any physicist’s training, help elucidate abstract concepts, introduce design principles, develop teamwork skills, and above all demonstrate the experimental nature of the subject [1]. At introductory undergraduate level these theoretical and experimental classes may easily have 50-100 students in a classroom working in close proximity. The emergence of Covid-19 now threatens this traditional structure of imparting physics and STEM education in general. The constraints of social distancing in a post-Covid era still allow online lectures delivered remotely, but no such effective strategy exists for laboratory training.

Computational physics has evolved as a third pillar of physics education and research after theoretical and experimental physics. A rise in computer-assisted data acquisition and simulations generates vast amount of data that can only be analyzed using scientific computing. With decreasing cost of computing power and storage, and increasing graphic rendering capabilities, detailed physical simulations can be run on laptops, tablets, and even on smartphones. Several initiatives have appeared in last two decades that utilize this opportunity to effectively communicate physical principles behind theory and experiments through physics-based applications and simulations run from an internet browser. We propose that a carefully curated collection of such interactive online resources can be used in conjunction with lectures where and when complimentary lab experiments are not possible.

Simulated virtual labs existed in rudimentary form for many decades, but have gained mainstream traction only recently [2]. In this article we introduce a number of open source computational physics resources that have been designed to supplement lectures and experiments. These resources emulate inner mechanics of several core concepts as well as laboratory experiments. Complemented with lectures these applets allow students to tune and visualize relationships between various control parameters of the underlying principles and see their physical effects immediately. Run as in-silico experiments these simulations can be used to generate data that can then be analyzed and reported by students using similar free online resources such as Google Drive.

1 ) PhET by University of Colorado, Boulder

PhET project was launched at University of Colorado, Boulder by Nobel Laureate Carl Weiman in 2002. Since then the project has added more than 150 interactive simulations that can be adapted for teaching experiments at school and university level. Though sometimes interacting with these simulations may give a feeling that you are playing a videogame, all the simulations are built on and aim to explain fundamental physical principles and concepts.

2) Open Source Physics – Singapore (OSP Singapore)

The OSP-Singapore page is maintained by Loo Kang Wee, and boasts of a large collection of simulations written in JAVA or Easyscript Java Simulations (EJS) [3]. The simulations can simply be run from a browser or can be downloaded and compiled locally. Quite a few simulations in this collection detail the use of various lab instruments. For example, simulations of Vernier calipers, micrometer screw gauges, among others, explain how to take measurements from these devices in presence of a tunable zero-error.

3) Open Source Physics (OSP)

The original OSP project started in 1998 and was sponsored by the National Science Foundation (USA), and Davidson College [4]. Originally it was introduced as a resource for teaching computational physics in JAVA through effective use of object-oriented programming paradigm, numerical programming libraries, and graphic libraries. Thanks to ease of deploying java-based scripts online the OSP evolved to be source of multiple online physics-based applets. One of the authors of this article (VY) co-taught a course based on OSP, where it was used as a platform to introduce advanced undergraduates and beginning graduate student to computational physics. Compared to PhET and OSP-Singapore, OSP requires a little more familiarity with computers, since one needs to download and compile the projects individually before interacting with them. On the brighter side, OSP also provides ample opportunity to build newer simulations by using other existing projects as a starting point.

Google Drive

Many of us already use Gmail for daily communications. An associated complimentary service included in Google Suite is Google Drive. It allows the user to remotely store and share up to 25 GB of data. It also provides free applications such as Google Docs, Google Sheets, and Google Slides which are similar to Microsoft Word, Excel, and PowerPoint respectively and can be adapted for analyzing, reporting, and presenting lab work. Since the lockdown, both VY and AD have extensively used Google Suite in their virtual classrooms where students analyze, report, present data and complete assignments.

An Example Exercise

Young’s double slit experiment can easily be identified as one of the most influential experiments in the history of physics. In a traditional lab setting, available at an undergraduate-level laboratory, the experiment would require at least a monochromatic source of light, a screen, a few engraved double slits of varying slit-widths and slit-separations. This experiment is also usually performed in a dark room unless the light source is a laser. The students usually set up this experiment and measure the distance between bright and dark interference fringes on a screen while varying the slit width, the distance between the two slits, and the distance between the slits and the screen.

Fig 1. Screenshot of a virtual double-slit experiment conducted by the authors on the PhET website

A simulated version of this experiment is available in PhET and can be accessed here. At the beginning of the simulation, a student can choose the third option from the selection menu and launch simulation of a double-slit experiment. The interactive controls allow the user to change the wavelength and the amplitude of light in use. Another set of controls allows the student to vary the slit width and the distance between the slits. The distance between the slits and the screen can be changed by dragging the slits towards or away from the screen. Once the desired configurations are achieved, the green button on left turns on the light source. The resulting interference pattern can then be visualized by selecting the screen and intensity plot options (Fig. 1). The simulation also provides a set of onboard tools to measure distances, time, and to visualize the electric field. Students can execute this simulation to measure how the distance between the interference fringes changes with control parameters such as, slit width, distance between the screen and the slits, and the wavelength of light used. They can estimate the distance using the onboard tools and keep a track of their measurements in a Google Sheet. This data can be analyzed, fitted and compared against theoretical results, examined for errors and reported remotely while maintaining the safety of the students, the instructor, and the lab staff.

Instructors can access a set of virtual labs and exercises utilized by Boston University’s Introductory Physics program and use it as a template for designing a virtual lab.

Limitations and benefits of a virtual lab

Even the most detailed simulation cannot replace an actual experiment. The familiarity with an instrument, and its proper handling are skills developed and mastered in a laboratory environment. Students need to practice skills such as leveling a balance, zeroing an instrument, and treating a surface, to understand their impact on an experiment. Without such a rigorous training we cannot even hope to produce next generation of experimental physicists.

However, if Covid-19 and its consequences are long-term, then we need a backup strategy for teaching STEM courses with limited to no lab resources. Virtual experiments may be our only option in that situation. Even if a timely intervention in form of a vaccine helps contain the spread of Covid-19, virtual experiments should become integral part of teaching toolbox of any instructor. They can be used as interactive modules to explain concepts and solve numerical exercises, or to introduce experimental and computational physics to undergraduate students. The opportunity to tune a large number of parameter combinations impossible in a regular three-hour lab setting can lead to novel experiment designs, and enhance students’ confidence in their experimental ability.

The demand for virtual labs is bound to increase in future. While the lockdowns caused by global pandemic have made it more apparent and urgent, this change is also driven by an emergence of activity-based STEM learning [5]. To fulfill this demand, we need to develop more virtual labs that are compatible with Indian educational system and standards. Computational research groups, educational publication houses and startups are well poised to rise to this challenge. This crisis has provided us with an unprecedented opportunity to reevaluate the prevalent educational practices and develop more efficient and effective teaching methodologies and strategies.

References

1. Natasha Holmes & Carl Wieman, “Introductory physics labs: We can do better,” Physics Today 71, 1, 38-42 (2018).
2. Jack M. Wilson, “Experimental simulation in the modern physics laboratory,” American Journal of Physics48:9, 701-704 (1980).
3. Garcia Clemente, Felix Jesus, Esquembre Martinez, Francisco Wee, Loo Kang, “Deployment of physics simulation apps using Easy JavaScript Simulations,” 2017 IEEE Global Engineering Education Conference (EDUCON), Athens, 2017, 1093-1096.
4. Tobochnik and H. Gould, “Teaching computational physics to undergraduates,” in Annual Review of Computational Physics IX, edited by D. Stauffer (World Scientific, Singapore, 2001), 275-323.
5. Angelo, C., Rutstein, D., Harris, C., Bernard, R., Borokhovski, E., Haertel, G. (2014). Simulations for STEM Learning: Systematic Review and Meta-Analysis (Executive Summary). Menlo Park, CA: SRI International.

Vikrant Yadav is a Postdoctoral Fellow in Department of Biomedical Engineering at Yale University. Asya Darbinyan is a Postdoctoral Fellow in School of General Studies at Stockton University. Views expressed are personal.

This article is part of a series called New Directions in Higher Education in India after COVID-19. The remaining articles of the series can be found here.