Making the Transition from Classical to Quantum Physics

Article excerpt

This paper reports on the nature of the conceptual understandings developed by Year 12 Victorian Certificate of Education (VCE) physics students as they made the transition from the essentially deterministic notions of classical physics, to interpretations characteristic of quantum theory.

The research findings revealed the fact that the understandings achieved by students were not always scientifically valid, or necessarily consistent with what had been taught in class. Analysis of the research data also revealed the fact that some of the students' mental constructions were in fact quite complex - often making use of a range of visual models and mathematical theories to make sense of quantum reality.

This area of research is of significant importance given the fact that quantum theory plays such a central role in our understanding of science and technology.

INTRODUCTION

Evidence gathered by researchers in the field of physics education, has shown that students' conceptual understandings are often at odds with scientific thinking. Many research studies on alternative conceptions in physics conducted during the past few decades (Duit & Haeussler, 1994; Gunstone, 1987; Van Heuvelen, 1991; Wandersee, Mintzes & Novak, 1994), have established the fact that the learning of physics concepts is problematic for students. This is particularly true of students who attempt to make the conceptual leap from the ideas of classical physics to those of quantum physics. Research scholars (Ambrose, Shaffer, Steinberg & McDermott, 1999; McDermott, 2001; Olsen, 2002) have highlighted significant mismatches between what is taught by teachers, and what is learnt by students in both senior high school and university quantum physics courses. Of particular concern to me in my role as senior physics teacher at a Melbourne secondary college, was the poor understanding of quantum concepts identified by international research relating to the study of the wave-particle duality of light and the wave nature of matter. Since quantum physics, in the words of Merzbacher (1970, p. 1) "... is the theoretical framework within which it has been found possible to describe, correlate, and predict the behaviour of a vast range of physical systems, from elementary particles, through nuclei, atoms, and radiation, to molecules and solids ...", I believe that it is essential for students to achieve an appropriate conceptual understanding of this extremely important branch of modern physics.

The purpose of my doctoral research was to examine the nature of student understanding of complex quantum concepts, particularly those associated with the study of the photoelectric effect, the wave particle duality and the wave nature of matter.

This paper reports on one aspect of my doctoral research - the nature of student understanding of concepts relating to their study of the wave-particle duality of light, and the wave nature of matter. This paper also reports on the implications of my research for improving the teaching and learning of quantum concepts.

BRIEF DESCRIPTION OF THE RESEARCH PROJECT

The Victorian Certificate of Education (VCE) Physics, Unit 4 area of study, Interactions of light and matter, involves the comprehension of highly abstract concepts. Students are expected to use scientific models and theories, in order to interpret evidence relating to interactions between light and matter. An appreciation of the concept of the wave-particle duality, as it applies to both light and matter, is central to this area of study. Mathematical modelling of physics phenomena is an integral part of this area of study.

In particular, students are expected to achieve familiarity with the following concepts as part of their studies:

* The photon model of light;

* The photoelectric effect;

* Young's experiment;

* Wave and particle models of light and matter; and

* Bohr's model of the atom and the quantisation of energy levels. …