Developing a Framework for Analyzing Definitions: A study of The Feynman Lectures

Abstract

One important purpose of a definition is to explain the meaning of a word. Any problems associated with a definition may impede students' learning. However, research studies on the definitional problems from the perspective of physics education are limited. Physics educators may not be aware of the nature and extent of definitional problems. As an example, The Feynman Lectures of Physics suggest that there are at least four problems of definition: precision, circularity, context and completeness in knowledge. Feynman had the tendency of mentioning the words ‘define’ and ‘definition’ and discussing the problems of definition: they can be insightful, or challenge the conventional, preconceived notions of many physical concepts. One benefit of this study is that a framework can be developed to improve statements of definitions. This framework may guide educators or students to analyze the knowledge that is embedded in a definition. In the future, the learning of definition need not be content-oriented, but problem-based instead, with the help of definitional problems. Therefore, the use of these problems of definition in lessons can be an interesting area for future physics education research. Furthermore, we should be cognizant of inadequacies or inaccuracies in definition that may result in alternative conceptions.

Keywords:

• Alternative Conception
• Content Analysis
• Definition
• Feynman
• Physics Education

Acknowledgement

We would like to thank the reviewers for offering constructive suggestions and valuable comments that have contributed to significantly improving this manuscript.

Notes

1. According to the Oxford English Dictionary, an ordinary word such as ‘force’ has 12 definitions including ‘violent action’, ‘physical strength’, ‘strong effect’, ‘power’ and ‘authority’ (Suzuki, 2005).

2. The problem of circularity in definitions can also be found in biology (Hengeveld, 2011) and chemistry (Duffus, Templeton, & Nordberg, 2009, p. 54). For example, International Union of Pure and Applied Chemistry was aware of circularity in the earlier definitions of‘speciation’.

3. In Levary et al.’s (2012) study, their first finding is that new concepts are introduced into language by the formation of loop structures or ‘cycles’ in the dictionary. The relationship between the concepts and loops reflects human intuition that new concepts must be self-contained, and the collection of words used to represent them must be self-referential. They divide the loops (or cycles) in the dictionary into two classes: short (≤5) and long (>5). Essentially, they explain that self-referencing in dictionary definitions exists not as a trivial artifact of a dictionary's construction but rather as the mechanism by which concepts are created and stored in language. In a sense, the problem of circularity in definition is not necessarily a fallacy.

4. Feynman's undergraduate physics lectures were a required course for Caltech freshmen and sophomores regardless of their majors, such as biology, chemistry, engineering, geology, mathematics and astronomy. There are different opinions on the usefulness of The Feynman Lectures, sometimes known as ‘the red books’. For example, in the words of Gleick (1992),

Colleges that adopted the red books dropped them a few years later: the texts proved too difficult for their intended readers. Instead, professors and working physicists found Feynman's three volumes reshaping their own conception of their subject. They were more than just authoritative.

On the other hand, a reviewer in Scientific American described The Feynman Lectures as ‘tough, but nourishing and full of flavour. After 25 years it is the guide for teachers and for the best of beginning students’ (Feynman, Leighton, & Sands, 2006, p. vii).

5. There is no agreement on the definitions of many physical concepts such as mass (Hecht, 2006; Sandin, 1991), entropy (Swendsen, 2011) and heat (Slisko & Dykstra, 1997).

6. Feynman's observations on the definition of magnetic field in textbooks from physics and engineering were not necessarily extensive. For example, there were also divisions within physics: some textbooks used Gaussian, physical or absolute system of units (Purcell, 1963), and currently more textbooks use International System of Units (Alonso & Finn, 1992). In addition, there is another confusion related to the term, magnetic field: in macroscopic media, Jackson (1999) names H-field as magnetic field and B-field as magnetic induction (p. 271). Alonso and Finn (1992) names H-field as magnetizing field and B-field as magnetic field (p. 708). Griffiths (1998) names B-field as magnetic field, and explains that H-field has no sensible name (p. 271). Simply put, magnetic field may be defined as H-field or B-field.

7. There is no agreement on the definition of mass as invariant or conserved (Hecht, 2006; Sandin, 1991). Morin (2007), for example, explains that

Of course, you can define the quantity γm to be anything you want … since there is in fact nothing actually wrong with using “relativistic mass”, it mainly comes down to personal preference whether or not you like the term … At any rate, my view is that these nice formulas don't outweigh the usefulness of having the word “mass” mean a very specific invariant quantity, with the word “energy” referring to the time-dependent quantity γm. Invariant quantities have a certain sacred place in physics, so they should be given a name that doesn't have any noninvariant connotations. (pp. 590–591)

8. In Feynman's letter to Armando Garcia J., dated 11 December 1985, Feynman wrote that ‘I am sure of nothing, and find myself having to say “I don't know” very often … It is fun to find things you thought you knew, and then to discover you didn't really understand it after all’ (Feynman, 2005, p. 396). This could also be explained by his belief that ‘there is always the possibility of proving any definite theory wrong’ (Feynman, 1965b, p. 157).

9. For example, we may pose this question to students which can be related to the problem of circularity: if the equation V = IR is used to define resistance, why is it not then possible to use the same equation to define potential difference? (Source: General Certificate of Education A Level 1995 June/Paper 3/Q4).