Identifying and Addressing Student Difficulties with the Millikan Oil Drop Experiment

Abstract

The Millikan oil drop experiment has been characterized as one of the ‘most beautiful’ physics experiments of all time and, certainly, as one of the most frustrating of all the exercises in the undergraduate physics laboratory. A literature review reveals that work done on addressing student difficulties in performing the oil drop experiment has, to date, not achieved a significant measure of success. The historical background of the oil drop experiment is well established in the literature from the perspective of historians of science, but not so from the perspective of teachers and students of science. A summary of historical details surrounding the original experiment suitable for use in revising the instructional approach is presented. Both Millikan and his graduate student, Fletcher, are featured with the view to emphasizing details that humanize the protagonists and that are likely to raise student interest. The issue of the necessary reliance on presuppositions in doing speculative research is raised, both from the historical account and from the insights of university physics students who heard the historical account and performed the experiment. Difficulties current students have in performing the experiment are discussed from the perspective of Hodson (Stud Sci Educ 22:85–142, 1993) framework and the students’ own observations. Last, further historical materials are outlined that may be used to encourage student insight into the fundamental nature of electricity. It is proposed that these aspects are essential as a basis for identifying and addressing student difficulties with the Millikan oil drop experiment.