The Oil Drop Experiment: An Illustration of Scientific Research Methodology and its Implications for Physics Textbooks

Abstract

The objectives of this study are:(1) evaluation of the methodology used in recent search for particles with fractional electrical charge (quarks) and its implications for understanding the scientific research methodology of Millikan; (2) evaluation of 43 general physics textbooks and 11 laboratory manuals, with respect to the oil drop experiment, based on seven history and philosophy of science criteria. Results obtained show that all the textbooks and manuals ignored the Millikan–Ehrenhaft controversy and in general lacked a history and philosophy of science perspective. In spite of the anomalous data, Millikan adhered to the guiding assumptions of his research program. Ehrenhaft's work strictly followed the logic of experimental observations. Although, Ehrenhaft's work approximated the traditional scientific method, the scientific community supported Millikan. General physics textbooks and laboratory manuals present the oil drop experiment as an example of the scientific method in which experimental data implicitly serves as an arbiter in the defense of Millikan. It is suggested that textbooks and manuals by including the Millikan–Ehrenhaft controversy and the methodology used in the search for quarks could enrich students' understanding of scientific research methodology, viz., experimental data do not always dictate the choice of a theory.