Review of the Scientific Method

1. Review of the Scientific Method

2. Scientific Method CONCEPT - an abstract or generic idea generalized from particular instances. FACT - something that has actual existence. For example space exploration is now a fact. HYPOTHESIS implies insufficient evidence to provide more than a tentative explanation. For example, a hypothesisexplaining the extinction of the dinosaurs. LAW implies a statement of order and relation in nature that has been found to be invariable under the same conditions. For example, the law of gravitation>. THEORY - a plausible or scientifically acceptable general principle or body of principles offered to explain phenomena. For example the wave theory of light> Chap0-Scientific Method-Revised 5/5/10

3. Scientific Method • Recognize a question or a puzzle - such as an unexplained fact. • Do some research and make an educated quess - a hypothesis - that mght resolve the puzzle. • Predict consequences of the hypothesis. • Perform experiments or make calculations to test the predictions. • Formulate the simplest general rule that organizes the three main ingredients: hypothesis, predicted effects, and experimental findings. Source: Conceptual Physics, Hewitt, 11th Ed., p.7 Chap0-Scientific Method-Revised 5/5/10

4. Scientific Method The scientific method is a way to ask and answer scientific questions by making observations and doing experiments. The steps of the scientific method are to: o Ask a Question o Do Background Research o Construct a Hypothesis o Test Your Hypothesis by Doing an Experiment o Analyze Your Data and Draw a Conclusion o Communicate Your Results It is important for your experiment to be a fair test. A "fair test" occurs when you change only one factor (variable) and keep all other conditions the same. http://www.sciencebuddies.org/mentoring/project_scientific_method.shtml Chap0-Scientific Method-Revised 5/5/10

5. Scientific Method http://www.sciencebuddies.org/mentoring/project_scientific_method.shtml Chap0-Scientific Method-Revised 5/5/10

6. Observation and Measurement • How do you know whether the earth is flat or round? • Is there any evidence that we can see from here? • Where would be the best place to find this evidence? • Hypothesis: the earth is round • Evidence: • Best place – on a large body of water – large, flat, level surface • Activity – watch a boat sail out over the horizon • Experimental Results: • Boat disappears sailing out – bottom first • Boat reappears sailing in – top first • Climbing to a higher vantage point brings the boat back into view. • These results are consistent with a round earth. The hypothesis is proved. Chap0-Scientific Method-Revised 5/5/10

7. Scientific Method • Hypothesis  Experiment  Results • A theory must explain currently known phenomena. • A theory must make predictions that can be tested. • Goals: • Theory as simple as possible • Few or no adjustable constants Chap0-Scientific Method-Revised 5/5/10

8. Scientific Method • As soon as a theory is established scientists start to investigate how far it can be stretched: • smaller dimensions, • larger dimensions, • larger and smaller masses. Theories are accepted as correct according to the currently available data but are also tested on new data as it becomes available Chap0-Scientific Method-Revised 5/5/10

9. Scientific Method • Disagreements with established theory sometimes arise • Initially attempt to modify the theory to fit in the new results • Try to add new concepts to theory • Discoveries are not always that orderly but can benefit from luck, accidents and a prepared mind. X-Rays were discovered when leaks in shielding exposed some nearby photographic plates. • Cosmic Background Radiation was discovered when trying to eliminate electrical noise in telephone transmission equipment. Chap0-Scientific Method-Revised 5/5/10