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Scientific method. Science v s. Pseudoscience. How do you know it's true?. W e each need a knowledge filter to tell the difference between what is true and what only pretends to be true. The best knowledge filter ever invented is science.
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Scientific method Science vs. Pseudoscience
How do you know it's true? • We each need a knowledge filter to tell the difference between what is true and what only pretends to be true. The best knowledge filter ever invented is science. • Science is not only a body of knowledge, but a way of investigating nature.
Scientific Method • The scientific method is a series of logical steps used to help solve problems or gain knowledge. • 1. It all starts with a question. • What do you want to know? • 2. Observe • Find out everything you can about the problem being investigated. • 3. Make a hypothesis • A possible explanation that would explain the observations. • 4. Test your hypothesis • Test with a controlled experiment (only one variable) or by further observations. • 5. Conclusion • Determine the validity of the hypothesis.
Applying the Scientific Method • Problem: Kelsey's car will not start. • Use the scientific method to find out why it will not start. • What would you look for if your car would not start? • Observation One: • The gas gauge is on empty. • Observation Two: • The lights come on, but they may not be as bright as usual.
Kelsey generates two hypotheses based on her observations. • Hypothesis A • The car will not start because it is out of gas. • Prediction of Hypothesis • Fill the tank with gas and the car will start. • Kelsey pours 2 gallons of gas into her car. It still will not start. • What do you conclude about the gas hypothesis? • Hypothesis B • The car will not start because the battery is dead. • Prediction of Hypothesis • Charging the battery or replacing the battery will enable the car to start.
Kelsey connects a battery charger to her battery. The battery will not charge. She takes the battery to a garage where it is diagnosed as a dead battery. • Kelsey installs a new battery. The car starts. • The hypothesis about a dead battery appears to be correct.
Pseudoscience • Pseudoscience – a theory or practice which is not supported by experimental evidence. • Examples: • Water-dowsing • Placebos (e.g., magnetic bracelets) • Astrology • Numerology • Polygraphy (lie-detector tests) • Handwriting Analysis • Biodynamic Agriculture
What is our role as scientists? “Every step taken by science claims territory once occupied by the supernatural. Where once we accepted storms and drought as divine will, there is now overwhelming scientific evidence that we ourselves can affect Earth’s climate.” - Robert Park, Professor of Physics, Univ. of Maryland “Man’s responsibility increases as that of the gods decreases.” - André Gide, French moralist
Scientific law – a statement of fact that describes an observation about nature and can sometimes be expressed as a mathematical equation. • Law of Gravity • Newton’s Laws of Motion • Laws of Thermodynamics • Law of Conservation of Matter and Energy • Scientific theory – a well-tested and widely accepted explanation of a natural event. • Big Bang Theory • Theory of Evolution • Quantum Theory of Light • Theory of Plate Tectonics
Writing Activity • Think about a question or problem you either had and solved or one you still have. • Write a paragraph about how you solved it or may be able to solve it using the scientific method. • When you are done, share your paragraph with your neighbor and listen to their story.
Exit Quiz • List the steps used by scientists to solve problems. 1. Make observations. 2. Ask a question. 3. Make a hypothesis, predicting your answer. 4. Test your hypothesis. 5. Interpret your results. Science Trivia: • Alexander Graham Bell advised Mark Twain to invest $5,000 in the telephone. Twain declined, saying he didn’t think telephones had “much of a practical future.”