1. 2 The Scientific Method Pushing back the frontiers of human knowledge.

2. 2 Goal What is science? What is the scientific method? Does the scientific method work? What is not a scientific argument. Why are you here?

3. 2 What is science? You see something happen, you ask why? You want to make something happen, you ask how? Science is a tool for answering why and how.

4. 2 Science as a tool Medicine: “I have high cholesterol, what should I do?” –Take cholesterol lowering medication. –Consult my astrologer. –Pray to the god Baal and sacrifice a goat.

5. 2 Tests and Theories Science is a tool for telling you what works! How do you know if your theory (idea, model, hypothesis) is right? –You can test it! A scientific theory must do two things: –Explain what is seen. –Predict what will happen in the future.

6. 2 The Scientific Method 1.Observe an event. 2.Develop a model (or hypothesis) which makes a prediction. 3.Test the prediction. 4.Observe the result. 5.Revise the hypothesis. 6.Repeat as needed. 7.A successful hypothesis becomes a Scientific Theory. model test

7. 2 Medical Science Scientific MethodHigh Cholesterol ObservationPatient has high cholesterol Hypothesis (prediction) Certain chemicals may dissolve cholesterol deposits. TestGive 100 patients these chemicals, give 100 patients placebo. Observe resultSame number lower their cholesterol as placebo patients. Revise hypothesis?Try different combo of chemicals. New test?Re-run medical test. Observe results. Scientific TheoryLipitor reduces cholesterol.

8. 2 Everyday Science Scientific MethodMaking Spaghetti Sauce ObservationSpaghetti sauce should be red. Hypothesis (prediction)Maybe try a tomato sauce. TestHeat pot of tomato sauce. Observe resultTaste the sauce - bland. Revise hypothesis?Use tomato sauce and garlic! New test?Add garlic, taste - not so bland. Scientific TheoryThe Final Recipe.

9. 2 Recap: Theories, Guesses, Laws What does the word “Theory” mean to you? “A conjecture; guess” (Webster’s Dictionary) Does it mean the same to a scientist? “A model which has been born out by repeated tests and observation.” Is a Theory less than a Law? “Evolution is just a theory, it is not a fact.” Do Theories “grow up” to be Laws? “Einstein’s Theory of Relativity”

10. 2 Theories So: a theory is a highly successful hypothesis. All hypotheses make predictions. All theories make predictions. All theories can be tested. Result: Any scientific theory is subject to change as our ability to make tests, or make observations of a test’s results, improves with time.

11. 2 Non-scientific Theories Make no predictions Un-testable Can’t be falsified The chain of events needed for life to arise is too complicated to have happened by chance, a divine intelligence must therefore have caused life to arise (Intelligent Design).

12. 2 Non-scientific Theories Cholesterol too high?  Aliens are clogging your arteries with invisible probes. Spaghetti is bland?  You were meant to eat bland food. Cholesterol too high?  Gods must be angry. Spaghetti is bland?  At the instant of tasting, tongue is transported to alternate dimension where all flavors are rendered nullified. Happens instantaneously.

13. 2 Non-scientific Theories The chain of events needed for life to arise are too complicated to have happened by chance, a divine intelligence must therefore have caused life to arise (Intelligent Design). Face on Mars. Viking Orbiter (1976)Mars Global Surveyor (1998)

14. 2 Falsification A real Scientific Theory tells you what observations are necessary to falsify it. –Not so proponents of: Face on Mars Moon Hoax Intelligent Design Astrologers

15. 2 Science on Mars Is Gusev Crater a dry lake bed?

16. 2 How is this different? From: English? Philosophy? Religion?

17. 2 Limits to Science What limits the questions science can answer? What types of questions can science not answer?

18. 2 Homework #2 Due Tuesday 1/20: Read Ty12 and Sg2. (Questions on class handout)