The importance of weightlessness and tides in teaching gravitation

American Journal of Physics

Volumn 71, Issue 11, 2003, Pages 1127-1135

  Galili, I ^a   Lehavi, Y ^a  

^a HEBREW UNIVERSITY OF JERUSALEM   (Israel)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 0242307906     PISSN: 00029505     EISSN: None     Source Type: Journal    
DOI: 10.1119/1.1607336     Document Type: Article

References (79)

1. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
2. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
3. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
4. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
5. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
6. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
7. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
8. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
9. A. L. King, "Weight and weightlessness," Am. J. Phys. 30, 387 (1962); F. W. Sears, "Weight and weightlessness," Phys. Teach. 1, 20-23 (1963); M. Iona, "The meaning of weight," ibid. 13, 263-274 (1975); "Weight - an official definition," Ibid. 37, 238 (1999); R. C. Morrison, "Weight and gravity - the need for consistent definitions, " ibid. 37, 51-52 (1999); R. Brown, "Weight - don't use the word at all," ibid. 37, 241 (1999); R. Bishop, "Weight - an accurate, up-to-date, layman's definition," ibid. 37, 238-239 (1999); A. Sokolowski, "Weight - a pictorial view," ibid. 37, 240-241 (1999); I. Galili, "Weight versus gravitational force: Historical and educational perspectives," Sci. Educ. J. 23, 1073-1093 (2001).
10. The force, which is measured by a calibrating scale. Standard weighing requires the body to be at rest and no additional interactions present.
11. An equivalent to this definition equates weight to mg*, where g* is a free fall acceleration as measured in a particular frame of reference (for example, F. J. Keller, W. E. Gettys, and M. J. Skove, Physics (McGraw-Hill, New York, 1993).
12. A. B. Arons, "Basic physics of the semidiurnal lunar tide," Am. J. Phys. 47, 934-937 (1979); M. M. Whithers, "Why do tides exist?" Phys. Teach. 31, 394-398 (1993).
13. A. B. Arons, "Basic physics of the semidiurnal lunar tide," Am. J. Phys. 47, 934-937 (1979); M. M. Whithers, "Why do tides exist?" Phys. Teach. 31, 394-398 (1993).
14. H. Härtel, "The tides: A neglected topic," Phys. Educ. 35, 40-45 (2000).
15. C. E. Swartz and T. Miner, Teaching Introductory Physics (AIP, Woodbury, NY, 1997), pp. 112-115. Tides were advocated to be included in high school programs. See C. Swartz, "Book report: Survey of high school physics texts," Phys. Teach. 37, 283-307 (1999).
16. C. E. Swartz and T. Miner, Teaching Introductory Physics (AIP, Woodbury, NY, 1997), pp. 112-115. Tides were advocated to be included in high school programs. See C. Swartz, "Book report: Survey of high school physics texts," Phys. Teach. 37, 283-307 (1999).
17. H. C. Ohanian and R. Ruffini, Gravitation and Spacetime (Norton, New York, 1994), pp. 38-54.
18. See for example, J. Cashatt, M. Harmon, L. Kluttz, A. Pitts, D. Saunders, D. Tesh, R. Wilkins, and S. Lea, "Weightlessness in free fall," Am. J. Phys. 43, 191-192 (1975); D. Chandler, "Weightlessness and microgravity," Phys. Teach. 29, 312-313 (1991); I. Galili, "Interpretation of students' understanding of the concept of weightlessness," Res. Sci. Educ. 25, 51-74 (1995); I. Galili and D. Kaplan, "Students' operation with the concept of weight," Sci. Educ. 80, 457-487 (1996).
19. See for example, J. Cashatt, M. Harmon, L. Kluttz, A. Pitts, D. Saunders, D. Tesh, R. Wilkins, and S. Lea, "Weightlessness in free fall," Am. J. Phys. 43, 191-192 (1975); D. Chandler, "Weightlessness and microgravity," Phys. Teach. 29, 312-313 (1991); I. Galili, "Interpretation of students' understanding of the concept of weightlessness," Res. Sci. Educ. 25, 51-74 (1995); I. Galili and D. Kaplan, "Students' operation with the concept of weight," Sci. Educ. 80, 457-487 (1996).
20. See for example, J. Cashatt, M. Harmon, L. Kluttz, A. Pitts, D. Saunders, D. Tesh, R. Wilkins, and S. Lea, "Weightlessness in free fall," Am. J. Phys. 43, 191-192 (1975); D. Chandler, "Weightlessness and microgravity," Phys. Teach. 29, 312-313 (1991); I. Galili, "Interpretation of students' understanding of the concept of weightlessness," Res. Sci. Educ. 25, 51-74 (1995); I. Galili and D. Kaplan, "Students' operation with the concept of weight," Sci. Educ. 80, 457-487 (1996).
21. See for example, J. Cashatt, M. Harmon, L. Kluttz, A. Pitts, D. Saunders, D. Tesh, R. Wilkins, and S. Lea, "Weightlessness in free fall," Am. J. Phys. 43, 191-192 (1975); D. Chandler, "Weightlessness and microgravity," Phys. Teach. 29, 312-313 (1991); I. Galili, "Interpretation of students' understanding of the concept of weightlessness," Res. Sci. Educ. 25, 51-74 (1995); I. Galili and D. Kaplan, "Students' operation with the concept of weight," Sci. Educ. 80, 457-487 (1996).
22. Galili and Kaplan in Ref. 8.
23. J. Viri, "Students' understanding of tides," Phys. Educ. 35, 105-109 (2000).
24. I. Galili and Y. Lehavi, "The importance of weightlessness and tides in teaching gravitation," in Science Education Research in the Knowledge Based Society, edited by D. Psillos, P. Kariotoglou, V. Tselfes, E. Hatzikraniotis, G. Fassoulopoulos, and M. Kallery (Kluwer Academic Publishers, Dordrecht, The Netherlands, to be published in 2003).
25. Although all the textbooks of the sample were published in the United States, the results are relevant to the country of the study, Israel, where the same textbooks are widely used.
26. D. Halliday, R. Resnick, and J. Walker, Fundamentals of Physics (Wiley, New York, 2001).
27. These findings match those reported by Morrison, Ref. 1.
28. A. French, "On weightlessness," Am. J. Phys. 63, 105-106 (1995).
29. U. Haber-Schaim, J. H. Dodge, R. Gardner, and A. Shore, PSSC Physics (Kendall/Hunt, Dubuque, IA, 1991), pp. 57-58.
30. H. Benson, University Physics (Wiley, New York, 1991), p. 86.
31. A. B. Arons, A Guide to Introductory Physics Teaching (Wiley, New York, 1990), pp. 71-73.
32. Reference 17, p. 84.
33. H. D. Young and R. A. Freedman, University Physics (Addison-Wesley, Reading, MA, 1996), p. 383.
34. The reluctance to use the term apparent for the weight might be interpreted in view of the everyday use of the terms apparent and true, as respectively imaginary (not sensed) and real (which is sensed), opposite to the conventional usage in physics.
35. This option is discussed in K. Taylor, "Weight and gravitational force," Phys. Educ. 9, 357-360 (1974).
36. For example, Ref. 16, pp. 58, 455.
37. R. D. Knight, Physics, Contemporary Perspective (Addison-Wesley, Reading, MA, 1997), p. 168.
38. See, for example, Bishop, Ref. 1, and L. S. Lerner, Physics for Scientists and Engineers (Jones and Bartlett, Sudbury, MA, 1996).
39. Sharing acceleration with a car does not make the driver weightless.
40. See for example, P. Hewitt, Conceptual Physics (Addison-Wesley, Reading, MA, 1998).
41. Reference 16, p. 455.
42. "Course contents in high school physics" (AAPT Committee on Special Projects for High School Physics, College Park, MD, 1988). A brief survey of physics textbooks published in the UK (6) and in Israel (5) testifies to a similar situation.
43. I. Galili and V. Bar, "Motion implies force. Where to expect vestiges of the misconception?" Sci. Educ. J. 14, 63-81 (1992).
44. Gardner reported that people with an engineering background account for the stationary circular motion by balancing gravitational force with centrifugal force. P. Gardner, "On centrifugal force," J. Aus. Sci. Teach. 27, 69-74 (1981).
45. This misconception was interpreted as being induced by the gravitational definition of weight not fortified by the notion of apparent weight. Galili and Kaplan in Ref. 8.
46. All students' and teachers' quotes were translated from Hebrew and thus might lose some of their authentic form.
47. See, for example, Chaps. 5 and 13 in Ref. 17 and Chaps. 4 and 12 in Ref. 20.
48. H. C. Ohanian, Physics (Norton, New York, 1989).
49. Ref. 17; P. M. Fishbane, S. Gaziorowicz, and S. T. Thoronton. Physics for Scientists and Engineers (Prentice-Hall, Englewood Cliffs, NJ, 1993); Ref. 27; Ref. 35; M. M. Sternheim and J. W. Kane, General Physics (Wiley. New York, 1991).
50. Ref. 17; P. M. Fishbane, S. Gaziorowicz, and S. T. Thoronton. Physics for Scientists and Engineers (Prentice-Hall, Englewood Cliffs, NJ, 1993); Ref. 27; Ref. 35; M. M. Sternheim and J. W. Kane, General Physics (Wiley. New York, 1991).
51. E. Mach, The Science of Mechanics (Open Court, La Salle, IL, 1989), pp. 255-264.
52. Fishbane et al. in Ref. 36, Ref. 27, Ref. 17, Sternheim and Kane in Ref. 36.
53. Reference 35.
54. Students give the same account for the results of weighing on the ground. mistakenly summing the attraction to the Moon with the attraction to the Earth. Galili and Kaplan, Ref. 8.
55. The account for tides by considering "circular motion around the common center of mass" is equivalent to "mutual free fall" (Ref. 17. p. 273).
56. The "one bulge" view is reported in Ref. 10.
57. A. diSessa, "Towards an epistemology of physics," Cognit. Instr. 10, 105-225 (1993); D. Hammer, "More than misconceptions: Multiple perspectives on student knowledge and reasoning, and an appropriate role for education research," Am. J. Phys. 64, 1316-1325 (1996).
58. A. diSessa, "Towards an epistemology of physics," Cognit. Instr. 10, 105-225 (1993); D. Hammer, "More than misconceptions: Multiple perspectives on student knowledge and reasoning, and an appropriate role for education research," Am. J. Phys. 64, 1316-1325 (1996).
59. There is a similar confusion regarding the meaning of weighing results. See for example, Galili and Kaplan in Ref. 8.
60. Reference 10 reported the prevalence of this reasoning.
61. In fact, a mere pull, such as in a homogeneous gravitational field, would not cause tides.
62. H. Reichenbah, The Philosophy of Space and Time (Dover, New York, 1927/1958), p. 223; Bishop in Ref. 1.
63. H. Reichenbah, The Philosophy of Space and Time (Dover, New York, 1927/1958), p. 223; Bishop in Ref. 1.
64. J. Piaget, The Child's Perception of Causality (Littlefield, Adams, Totowa, NJ, 1969).
65. The Practice of Constructivism in Science Education, edited by K. G. Tobin (Lawrence Erlbaum, Hillsdale, NJ, 1993); Constructivism in Science Education, edited by M. Matthews (Kluwer, Dordrecht, Netherlands, 1998).
66. The Practice of Constructivism in Science Education, edited by K. G. Tobin (Lawrence Erlbaum, Hillsdale, NJ, 1993); Constructivism in Science Education, edited by M. Matthews (Kluwer, Dordrecht, Netherlands, 1998).
67. See for example, Brown in Ref. 1.
68. A. I. Miller, Imagery in Scientific Thought (MIT Press, Cambridge, MA, 1986).
69. A. Eisenkraft and L. D. Kirkpatrick, "Weighing an astronaut," Quant. 5, 36-39 (1995), p. 37.
70. Bloom's taxonomy states that the knowledge of definitions requires low-level cognitive resources. See B. S. Bloom, M. D. Engelhart, H. H. Hill, E. J. Furst, and D. R. Krathwhol, "The taxonomy and illustrative materials," in Taxonomy of Educational Objectives. The Classification of Educational Goals, Handbook 1: Cognitive Domain, edited by B. S. Bloom (McKay, New York, 1956).
71. Also in Morrison, Ref. 1.
72. J. Schwab, "Structure of the discipline: Meaning and significance," in The Structure of Knowledge and the Curriculum, edited by G. W. Ford and L. H. Pugno (Rand McNally, Chicago, 1964), pp. 6-30.
73. L. S. Shulman, "Those who understand: Knowledge growth in teaching," Educ. Res. 15, 4-14 (1986).
74. H. Margenau, The Nature of Physical Reality (McGraw-Hill, New York, 1950), pp. 220-244.
75. The claim that "the earth is weightless" contradicts the intuition of students (Galili and Kaplan, Ref. 8). It also conflicts with the common reference to Cavendish's measurement (1787) of the gravitational constant as "weighing of the Earth."
76. M. Sawicki, "Myths about gravity and tides," Phys. Teach. 37, 438-441 (1999).
77. The calculations providing this result are similar to those appeared in Ref. 7, pp. 38-54.
78. Reference 7.
79. See for example, K. A. Kulikov, Fundamental Constants of Astronomy (English translation Israel Program for Scientific Translation, Jerusalem, 1964, Translated from the Russian "Gosudarstvennoe izdatel'stvo Tekhniko-teoreticheskoi literatury," Moskva, 1956). pp. 99-101.