THE NATURE OF SCIENCE

1. THE NATURE OF SCIENCE

2. The Method of Science

3. Science – process that uses observation and investigation to gain knowledge about events in nature

4. Scientific Method An organized set of investigation procedures used by scientists

5. Hypothesis-educated guess or testable prediction • A suggested solution to the problem. • Must be testable • Sometimes written as If…Then… statements • Predicts an outcome

6. Hypothesis • An example of a hypothesis might be that the salamanders have curved tails due to a pollutant in the moist soil where they live.

7. Experiment-organized procedure to test the hypothesis • A procedure to test the hypothesis.

8. Scientific Experiments Follow Rules • An experimenter changes one factor andobserves or measureswhat happens.

9. Experiment Variable – factor in the experiment that is being tested

10. The Control Variable • The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. • Those factors are called control variables.

11. What is the Purpose of a Control? • Controls are NOT being tested • Controls are used for COMPARISON

12. Other Variables • The factor that is changed is known as the independent variable. • The factor that is measured or observed is called the dependent variable.

13. Example of Controls & Variables • For example, suppose you want to figure out the fastest route to walk home from school. • You will try several different routes and time how long it takes you to get home by each one. • Since you are only interested in finding a route that is fastest for you, you will do the walking yourself.

14. What are the Variables in Your Experiment? • ______________is the independent variable • ______________is the dependent variable • ________________a control variable.

15. Experiment A good or “valid” experiment will only have ONE variable!

16. Data • Results of the experiment • May be quantitative (numbers) or qualitative

17. Data • Must be organized • Can be organized into charts, tables, or graphs

18. Conclusion • The answer to the hypothesis based on the data obtained from the experiment

19. Retest In order to verify the results, experiments must be retested.

20. Scientific Law vs. Scientific Theory Explanation based on experiments – most logical explanation Ex. Black Hole Theory Rule of nature that sums up related observations to describe a pattern in nature Ex. Law of Gravity

21. Scientific Theory and Scientific Law • The field of biology has more scientific theories that result from research. • The fields of chemistry and physics have more scientific laws that result from research. Cell Theory Charles’s Law: V1/T1 = V2/T2 Evolutionary Theory

22. Scientific Theory and Scientific Law • Scientific Theory usually describes a phenomenon seen in nature. • Scientific Law usually explains how a process works under a given set of conditions with a mathematical formula. New cells form from existing cells Force is the product of an object’s mass and acceleration BOTH are proven true through continuous experimentation!

23. The speed of light in a vacuum is constant and an absolute physical boundary for motion Question: Mass can come from energy and energy from mass (E= mc2) Is this a scientific theory or a scientific law? Scientific LAW Is this a scientific theory or a scientific law? Part of the THEORY of relativity

24. Question: Is a scientific theory or a scientific law more correct? Trick question! Both are equally proven to be true through continuous experimentation.

25. STANDARDS OF MEASUREMENT

26. International System of Units (SI) Standard system of measurement used worldwide

27. Length – Distance between two points Volume – The amount of space occupied by an object Mass – Amount of matter in an object Density – Mass per unit volume of a material Time – Interval between two occurring events

28. 1 2 3 MetersLitersGrams How do you use the “ladder” method? 1st – Determine your starting point. 2nd – Count the “jumps” to your ending point. 3rd – Move the decimal the same number of jumps in the same direction. Starting Point Ending Point __. __. __. 2 3 1 Ladder Method KILO1000Units HECTO100Units DEKA10Units DECI0.1Unit CENTI0.01Unit MILLI0.001Unit 4 km = _________ m How many jumps does it take? 4. = 4000 m

29. Compare using <, >, or =. 56 cm 6 m 7 g 698 mg Conversion Practice Try these conversions using the ladder method. 1000 mg = _______ g 1 L = _______ mL 160 cm = _______ mm 14 km = _______ m 109 g = _______ kg 250 m = _______ km

30. Metric Conversion Challenge Write the correct abbreviation for each metric unit. 1) Kilogram _____ 4) Milliliter _____ 7) Kilometer _____ 2) Meter _____ 5) Millimeter _____ 8) Centimeter _____ 3) Gram _____ 6) Liter _____ 9) Milligram _____ Try these conversions, using the ladder method. 10) 2000 mg = _______ g 15) 5 L = _______ mL 20) 16 cm = _______ mm 11) 104 km = _______ m 16) 198 g = _______ kg 21) 2500 m = _______ km 12) 480 cm = _____ m 17) 75 mL = _____ L 22) 65 g = _____ mg 13) 5.6 kg = _____ g 18) 50 cm = _____ m 23) 6.3 cm = _____ mm 14) 8 mm = _____ cm 19) 5.6 m = _____ cm 24) 120 mg = _____ g

31. Compare using <, >, or =. 25) 63 cm 6 m 27) 5 g 508 mg 29) 1,500 mL 1.5 L 26) 536 cm 53.6 dm 28) 43 mg 5 g 30) 3.6 m 36 cm

32. Strategies for Reading the Ruler

33. Background – World Wide • Two main systems of measurement • Metric System • Based on the number 10 • U.S. Customary System • Based on halving or doubling units

34. Background – World Wide • What countries besides the U.S. have not adopted the metric system? • All countries have adopted the metric system, including the United States. However, in nearly all countries people still use traditional units. For a country to switch to metric is a process that happens over time. Only 3 countries in the world, have not officially adopted metric as their primary system of measuring.

35. Background – United States • The U. S. has switched to Metric with • Sporting Events - Olympics • Military • Medicine • Scientific studies

36. Background – United States • At this time, Manufacturing; Transportation; and Construction Industries; are primarily using the U.S. Customary system. In certain sectors, the conversion is obvious (i.e. – Automobiles). However, in these industry areas the changes have not been as complete. • This is the reasoning for studying both measurement systems used in the United States.

37. Protractor Tape Measure Yard Stick Architect's Scale Meter Stick Framing Square Background – United States • Devices that you can measure with- such as a ruler…….

38. Lets find this point! Metric Details • Millimeters and Centimeters • 10 millimeters = 1 Centimeter • 10 Centimeters = 1 Decimeter 1 2 2 centimeters

39. Lets find this point! Metric Details • Millimeters and Centimeters • 10 millimeters = 1 Centimeter • 10 Centimeters = 1 Decimeter 1 8 2 7 3 6 4 8 millimeters 5

40. Lets find this point! Metric Details • Millimeters and Centimeters • 10 millimeters = 1 Centimeter • 10 Centimeters = 1 Decimeter 1 10 Centimeters or 1 Decimeter

41. Reading the Graduated Cylinder And All about the Meniscus

42. Reading the Graduated Cylinder • Liquids in glass and some plastic containers curve at the edges • Changing the diameter of the cylinder will change the shape of the curve • This curve is called the MENISCUS

43. Reading the Graduated Cylinder • Your eye should be level with the top of the liquid You should read to the bottom of the MENISCUS

44. Practice Reading the Graduated Cylinder • What is this reading? 18.0 ml

45. Practice Reading the Graduated Cylinder • What is this reading? 36.5 ml

46. Practice Reading the Graduated Cylinder • What is this reading? 42.9 ml

47. Practice Reading the Graduated Cylinder • What is this reading? 47.0 ml

48. Practice Reading the Graduated Cylinder • What is this reading? 61.2 ml

49. GRAPHING

50. Graph A visual display of information or data.