Nature of Science

1. Nature of Science Joel A. Bryan, Ph.D. Center for Mathematics and Science Education Texas A&M University jabryan@tamu.edu

2. SCIENCE is… the search for relationships thatexplain andpredictthe behavior of the universe.

3. Science has also been described as the process of model building, in which models serve to simplify observed phenomena and relationships. Scientific “models” may exist in several forms: Physical (concrete; 3D objects) Gestural (kinesthetic; body movements) Verbal (spoken/written text; analogy; metaphor) Pictorial (visual diagrams; animations) Numerical (data table) Graphical (ordered pairs) Mathematical (formula)

4. PHYSICS is… the science concerned with relationships betweenmatter, energy,and its transformations.

5. TEKS Scientific Process Skills – All Grades http://www.tea.state.tx.us/rules/tac/chapter112/index.html K-5 TEKS; 6-8 TEKS TAKS Objective 1 – Grades 5, 8, and 10 “The student will demonstrate an understanding of the nature of science.” Science for All Americans (link) http://www.project2061.org/publications/sfaa/online/chap1.htm Benchmarks for Science Literacy (link) http://www.project2061.org/tools/benchol/ch1/ch1.htm

6. Scientific Hypothesis Most people agree that a scientific hypothesis can be defined simply as an educated guess. We should, however, stress that it is educated, meaning that there are plausible reasons for that decision.

7. Scientific Theory There is much misunderstanding about what constitutes a scientific theory. “In science, a theory is a proposed description, explanation, or model of the manner of interaction of a set of naturalphenomena, capable of predicting future occurrences or observations of the same kind, and capable of being tested through experiment or otherwise falsified through empirical observation.” Taken from http://en.wikipedia.org/wiki/Theory.

8. Scientific Law A scientific law has been described as a statement describing a natural event. In many cases, scientific laws serve to DESCRIBE an event, while scientific theories seek to EXPLAIN the event. It is NOT a question of TRUTH.

9. The Scientific Method • Many students of all ages are taught that “the scientific method” consists of steps such as: • Make an observation • Formulate a hypothesis • Test the hypothesis • Evaluate the hypothesis • Change the hypothesis and/or make more tests • It is important to note that scientific study involves a systematic process of experimentation and evaluation, whether you begin with a hypothesis or with “trial and error.”

10. “It is the year 2347. The Earth’s natural resources are exhausted. Scientists have determined that the Earth will most likely explode in a very short time.” Bang!!!

11. “The development of space travel and other technological advancements have enabled scientists to prepare a distant planet for human habitation.”

12. “You and a few others are fortunate to have been selected as representative members of planet Earth who will survive and populate this new distant planet.”

13. “Upon arrival, you are relieved to find that the planet is indeed suitably prepared for human existence, just as promised.”

14. “Your joy soon turns to frantic dismay when you discover that the sole member of your team with knowledge of the voice- activated oxygen producing machine has taken deathly ill and no longer remembers the voice activation code.”

15. “As your oxygen supply quickly depletes, a close inspection of the voice- activated oxygen supply machine reveals only a few vague instructions.” Speak here. Oxygen Instructions

16. “Oxygen is produced by spoken numerical code, of which no number may be used more than once. Five consecutive invalid attempts will cause this device to completely self-destruct. Press here to begin, speaking loudly and clearly into the microphone.”

17. Your task is to begin the process of trying to determine the “code,” or rule, that determines whether or not a number is valid for oxygen production.

18. WorksDoesn’t Work 2,4,6, 1,3,5, For example, these numbers might suggest to some viewers that even #’s work and odd #’s do not.

19. Participants should begin with a “trial and error” type process that quickly leads them to form some kind of theory regarding what constitutes “successful” numbers. Both successful and unsuccessful responses should be recorded for ease of evaluation.

20. Participants must then go through a “scientific” process of testing, evaluation, and modification of their theories. This process should illustrate what is commonly referred to as the “scientific method,” along with many attributes of the “nature of science.”

21. This activity provides opportunities during the entire process to illustrate aspects of the nature of science. Additional time should be taken at the end of the exercise to reflect on the nature of science as evidenced by this activity. The following is a brief discussion of how this activity illustrates some aspects of the nature of science.

22. Nature of Science aspects reinforced by this activity include, but are not limited to: • Scientific conclusions depend on the creative imagination of the scientist.

23. Science is a social enterprise. • Scientific knowledge is dynamic and subject to change. • Absolute certainty of a scientific conclusion is an impossibility.

24. Scientific conclusions depend on the creative imagination of the scientist. • Participants were limited in • their creativity by what they • had previously experienced • with numbers.

25. Each participant looked at the • exact same “evidence,” yet • depended on their own experiences • and creative imagination to • determine the “reality” of what • the numbers actually represented. • This naturally led to differing • interpretations of the same • “reality.”

26. For Discussion In what ways are the “creative” aspects of this activity similar to “creative” aspects of “real” science? In what ways are they different? How might prior experiences influence scientific interpretations? Provide some possible examples.

27. Science is a social enterprise. • Because repeated failure would • be detrimental to the health • of all, it was necessary for • participants to reach some type • of consensus before attempting • a “trial.”

28. Participants were forced to • evaluate competing theories • and determine the most plausible. • This decision may not have always • been made on the basis of merit • alone.

29. For Discussion In what ways are the social aspects of this activity similar/different to the social aspects of “real” science? How are differences of opinion settled in scientific issues? Provide some possible examples.

30. Scientific knowledge is subject to change. • A “theory” remains valid as • long as it explains prior • findings and is useful in • predicting new ones.

31. The “theories” were valid and • useful until new “discoveries” • proved them wrong. • Theories may undergo slight • change or total abandonment • when confronted with • discrepant evidence.

32. For Discussion In what ways are the aspects of theory change in this activity similar/different to the theory change aspects of “real” science? How does one decide whether to abandon or modify an existing theory? Provide some possible examples.

33. Absolute certainty of a scientific claim is not possible. • No amount of trials could ever • prove one theory totally correct. • Only one counterexample was • needed to invalidate a theory.

34. No one will ever • know with absolute • certainty the true • “rule” for the • oxygen machine • without seeing • the “card.”

35. For Discussion In what ways are the uncertainties of this exercise similar/different to that of “real” science? What would “seeing the card” mean? Will scientists ever “see the card?” Provide some possible examples.