The Nature of Science and The Scientific Method

1. The Nature of Science and The Scientific Method Chemistry – Lincoln High School Mrs. Cameron

2. The Purpose of Science: Is to create models that explain natural phenomena. Model = theory = explanation

3. So you’ve decided to study chemistry – Or have you?

4. ~You have always been a scientist ~

5. ~ Haven’t you? ~

8. So when did “mankind” begin to study science?

9. Beginnings of Science. • Science has roots in philosophy http://2.bp.blogspot.com/-FlMgZcIBR0M/Th2Jv3u11XI/AAAAAAAAAOE/G9gdYevwCEk/s1600/Le+penseur.jpg

10. Philosophical questions: philosophy.columbian.gwu.edu%252Fphilosophical-questions%3B556%3B703

11. Socrates Socrates – “academios” (grape arbor) http://www.penick.net/digging/images/2010_09_06_Wildflower_Center/Grape_arbor.JPG

12. Socrates We learn by generalizing. We come to knowledge through logic. Syllogisms: Three statement arguments – (2 statements organized to make a third.) Girls have long hair. Mary has long hair. Mary must be a girl. http://1.bp.blogspot.com/_qUvh8vgMY4Y/TC9jS3MwwKI/AAAAAAAAASY/NdpkyzjRafE/s1600/61.jpg

13. Plato - Socrate’s student. - What is reality? Anything that changes is not real. The only way to acquire knowledge is to study what is real. http://www.towerbabel.com/media/photos/cache/plato_1_320x320.jpg

14. What are things that change in this world? Is there anything that doesn’t change? http://4.bp.blogspot.com/-5scsHjiAJdg/UCfbsaKpDfI/AAAAAAAAD7A/fBvVsv0X4Es/s1248/1.jpg

15. Aristotle • Reality changes so therefore • Knowledge must change also. • Reality is experienced, physical reality. • There is no limit to what you can know.

16. Science vs Philosophy Science Philosophy Asks questions that may or may not be able to be tested. Philosophical thinking is open ended May be based on opinion • Ask questions that can be tested • Scientific thinking involves • observations • defining a problem • construction of explanations • evaluation of possible explanations or solutions to the problem

17. Albert Einstein – There is a limit to what you can know. And here’s why….

18. The Nature of Science – Inductive and Deductive Reasoning and The Scientific Method

19. Deduction or Deductive Reasoning – Start with general principle, see if individual fits generality. Ex. Mathematical Proofs, Is Pluto a planet? https://www.google.com/search?q=pluto&espv=2&biw=1440&bih=775&tbm=isch&tbo=u&source=univ&sa=X&ei=eZ8JVPmFGOrCsATR2oGoBQ&ved=0CEMQsAQ#facrc=_&imgdii=_&imgrc=XquaM_Sjr7OeiM%253A%3BYekJOp8nnlRooM%3Bhttp%253A%252F%252Fwww.magicalears.com%252Fclipart%252FClassic%252520Characters%252FPluto%252Fpluto001.gif%3Bhttp%253A%252F%252Fwww.magicalears.com%252Fclipart%252FClassic%252520Characters%252FPluto%252F%3B1043%3B589 http://rofl-lol.com/cartoon-planet-pluto/

20. Faulty Deductions: https://www.google.com/search?q=deductive+reasoning&espv=2&biw=1440&bih=775&source=lnms&tbm=isch&sa=X&ei=l54JVNWSH7SIsQSXzYHYAw&ved=0CAcQ_AUoAg#facrc=_&imgdii=_&imgrc=lG0wiya_oikhcM%253A%3BHB4xtbvr3XJKMM%3Bhttp%253A%252F%252F1.bp.blogspot.com%252F_RS7AxrV5uuc%252FSdjEiptsQQI%252FAAAAAAAAADI%252FIj1YAAl-CbM%252Fs400%252Fpenguin_syllogism.jpg%3Bhttp%253A%252F%252Fkjwtokjournal.blogspot.com%252F2009_04_01_archive.html%3B355%3B400

21. Induction or Inductive Reasoning – Specific observations lead to generalizations. Ex. Space ship visiting the high school Caveman story - The generalization has to fit the observations….

23. When do you have enough examples or observations? • Need all examples to reach certainty. • Never reach “certainty” • Inductive leap – Can’t examine all examples. • This means the generalization must change when an observation does not fit the generalization.

24. Models A model is the best possible explanation which accounts for all observed phenomenon and has predictability. • An unanswered question means change the model. • Predictability is the test of a good or “true” model. • Occham’s Razor – of 2 possible explanations, choose the simpler.

25. If the purpose of science is to create models that explain natural phenomena, then by it’s very nature it changes. • You can’t equate science with God, or faith or things that don’t change. • You can’t equate science with the truth.

26. Science is not philosophy – it is based on observations and uses an organized, methodical method to explain the natural world.

27. The Scientific Method Uses both inductive and deductive reasoning. http://markread.info/wp-content/uploads/2013/10/science-dog.png

28. The Scientific Method • A method to solve problems • A method to make models • A method to answer questions • A method to explain natural phenomena

29. Steps in the Scientific Method • Observe 2. Ask a question or state a problem based on observations 3. State a hypothesis (must be able to be tested!)

30. 4. Test the hypothesis by designing and performing experiments. 5. Analyze results 6. Share the results and conclusions with others.

31. The scientific method is a guideline – sometimes scientists do things out of order! • Both inductive and deductive reasoning are used at different times. • Experiment design follows guidelines too.

32. Experiment Design • Independent Variable – condition changed by experimenter • Dependent Variable – responds to the independent variable • Control – holds everything but the variables constant so you can see if the variable has an effect on the outcome of the experiment.

33. Observations and Evidence • Objective – State only what really happens (no bias or opinion) • Repeatable – When the same procedure is repeated by others, they obtain the same results.