THE NATURE OF SCIENCE

1. THE NATURE OF SCIENCE Understanding and Teaching Biological Sciences Summer 2009

2. What is Science? “A field of study based on memorization of boring facts that have little relevance to my life. People who are almost always right, never unsure of them, relatively emotionless, and often arrogant, practice it. They are not at all like me.” (A student, NABT Conference, 2009)

3. Science as a way of knowing! Research suggests that most students do not adequately understand the nature of science (McComas, 1996; Moore, 1993; Horner & Rubba, 1979). Understanding “what science is and what its limits are” must be a key component of science teaching and learning (Moore, 2009).

4. NATURE OF SCIENCE • How is science different from other ways of knowing? • Why is important to know and understand the epistemology of science? • How is knowledge constructed in science?

5. The Portrait of Science The scientific Worldview • The natural world works in “consistent patterns” • Events, and phenomena are interconnected • The universe is a “vast single system”; knowledge gained from studying one part of it can often be applied to other parts • Scientific ideas are constantly tested against nature • Scientific theories are tentative and subject to change or modification through new observations, data, and evidence (AAAS, 2004)

6. Scientific Knowledge: Continuity, Stability, and Evolution • Scientists are able to make accurate predictions about the natural world by building scientific models and theories to explain natural phenomena • Scientists rely on physical cause and effect only - Scientific models are approximations of nature • The role of physical evidence in science • Scientists often disagree over evidence interpretations of data, and inferences

7. Nature of Science • Scientific theories are debated, contested, revised, and sometimes replaced in the light of new evidence/data • The role of new inventions, tools, and technology in advancing scientific knowledge • Theories are judged by their results • How is scientific knowledge communicated? Conferences, Journals (AAAS, 2004) Can science explain spiritual and religious questions/ideas?

8. Normal science vs. Scientific revolutions • Normal science is a puzzle solving activity where scientists solve “empirical puzzles” within the framework of an over-arching paradigm • Problem-solving an attempt to reduce the gap between observation and theory • Normal science research is “cumulative” • Those problems are usually selected which can be solved using the “existing paradigm, technique,” and technology (Kuhn, 1992)

9. Crisis in science “Crises are a necessary precondition for the emergence of novel theories” (Kuhn, 1992) • Nature vs. conceptual paradigms; discrepancies between observation and predictions • Anomalies, conflicts, contradictions, and “counter instances” emerge • Further “articulations” and “ad hoc modifications” of the existing theory • Anomalies persist and also resistant to be incorporated into existing paradigms; result a crisis (Kuhn, 1992)

10. Early Chemistry • Earth • Air • Fire and • Water

11. Role of anomalies in generating a crisis (1) Early chemical theory of fire • All combustible substances composed of a substance called phlogiston (from Greek, meaning "burned"). • The phlogiston theory explained numerous physical and chemical phenomena • Explained why metals had common properties • phlogiston produced common properties • Explained why substances burned - Burning was caused by the liberation of phlogiston from the substance - Ash or residue was “dephlogisticated.”

12. New theories • Lavoisier (1780) refuted the phlogiston theory. His experiments (1780) led to the view that matter is not a “structure less continuum.” • Transformations of matter could be investigated quantitatively by measuring the masses of substances consumed and produced in reactions; total mass same; law of fixed proportions, conservation of mass.

13. Reconceptualizing Chemistry • Dalton (1803) finally developed the atomic theory; explained physical and chemical changes • Chemical reactions involved combination and separation of atoms, in simple whole number ratios. “Scientists stopped writing that the oxides of carbon (CO and CO2) contained 56% and 72% of oxygen by weight” (Kuhn, 1992) • A completely new way of conceptualizing and practicing chemistry

14. Scientific revolution • A valid paradigm is renounced only when an “alternate candidate” is available to take its place • New theory should make different predictions • After the revolution, scientists’ need to be “re-educated” to understand the world through the new paradigm E.g. Copernican heliocentric paradigm changed the meaning of the term planet; celestial bodies including the sun, stars, and planets were seen very differently • New technology also opens up avenues for new observations and testing

15. Falsificationism “The criterion of scientific status of a theory is its falsifiability, refutability, or testability” (Karl Popper, 1963) • “Easy to obtain confirmations, or verifications, for nearly every theory - if we look for confirmations” only • “Confirmations should count only if they are the result of risky predictions”; E.g., Einstein’s gravitational theory & Eddington’s expedition measuring predicted deflected light • A theory is “non-scientific” if it is not refutable” • Irrefutability not a “virtue, but a vice.”(Popper, 1963)

16. Progressive vs. Degenerative Theories Theories are not always refuted, but replacedby better theories Scientists are engaged in rival research programs • Hard Core (“Unchangeable and unchallengeable ideas”) –Central Idea –Difficult to test directly –Protected from refutation by ‘protective belt’ of auxiliary hypotheses • Auxiliary Hypotheses: –‘Protective Belt’ of research program –Which problems to pursue - sets of puzzles to solve (Lakatos, 1978)

17. Progressive vs. Degenerative research Programs •Progressive –New Theory consistent with all of known facts –New Theory predicts new facts –Empirical support of new predictions •Degenerative –New theory only generated after some novel observation –Lack of empirical support for new predictions

18. Discussion Points • What features of scientific inquiry would you like to highlight in your own classes or in other biology/science classes at your school?