Can virtual labs become a new normal? A case study of Millikan's oil drop experiment

The present digital era has brought a paradigm shift in the learning behaviour of students and has provided innovative teaching and learning strategies that extend beyond the four walls of a classroom or a laboratory. One such innovation is the implementation of online or virtual laboratories. A virtual lab is seemingly an economically feasible and effective means to reach out to large audiences in schools, colleges, and universities. In a virtual lab, software simulates the lab environment and provides a step-by-step opportunity to perform an experiment, which can be performed anywhere, any time, on mobile or a notebook or a laptop. Millikan's oil drop (MOD) experiment is one of the key experiments performed in the broad area of modern physics by undergraduate students to estimate the value of charge on an electron and confirm its quantization. Performing this landmark experiment requires good hands-on experimental skill with a lot of patience. It involves managing various parts of the equipment in sync with an effort to keep a charged oil drop in the field of view of the telescope in the presence of gravitational force, buoyant force, viscous force of air and electric force. It simultaneously requires recording of the observations during the upward and downward motion of the charged drops. This paper presents a study to understand the efficacy of performing the MOD method in a virtual environment vis-a-vis the learning outcomes of the students. The study revealed that there was an improvement in the conceptual understanding of the students. The students appreciated the use of the virtual lab, but at the same time they did not see it as a replacement for the traditional method involving an actual laboratory and teachers: they still have an urge to touch and feel the real apparatus in the presence of a human facilitator to clear their doubts.