1.2 The Scientific Method

Why Science?

“An expert is a person who has made all the mistakes that can be made in a very narrow field.” ― Niels Bohr, Danish Physicist who made important contribution to atomic structure

Science is….. Pursuit of Knowledge Mistakes (You will be wrong.) Continuous Improvement Controversial

History of the Scientific Method Scientific componenets go back as far as 1600 BC where examination, diagnosis, treatment and prognosis were used in Egyptian Medical texts. Aristotle – 300s BC - Inductive (from observation) and Deductive (from thought) approach. The purpose was to gain knowledge.

History of the Scientific Method Ibn al-Haytham (Alhazen) – Arab Physicist – published Book of Optics in 1021 AD that combined, observations, experiements, and rational arguments. Showed light traveled from objects to eyes rather than being emmitted from the eye. Viewed his studies as a “search for truth.”

History of the Scientific Method Robert Grosseteste – 1100s – introduced Aristotles methods to Europe Roger Bacon – 1200s – described the repeating cycle of observation, hypothesis, and experimentation Francis Bacon – 1561 – 1626 – devotes scientific process to experimentation

History of the Scientific Method Descartes - Day-cart(late 1500s), Galileo (late 1500s -1600s), Newton (late 1600s – 1700s) continued to develop “rules” for how to explore our world. Charles S. Pierce (late 1800s) pioneered the idea of combining deductive and indictive reasoning together and using statistics to measure scientific probabilities.

History of the Scientific Method 1900s – ideas such as randomized design, controlled placebo, and computer simulation gain popularization. Which brings us to where we are today…..

7 Steps to the Scientific Method 1. State the Problem 2. Make Observations 3. Form a Hypothesis 4. Test the Hypothesis 5. Collect and Record Data 6. State a Conclusion 7. Repeat the Process

Step #1: Stating the Problem Maybe the most important step Start by asking a question

Step #2: Make Observations Observation: Perceiving objects or events through 1 of your 5 senses Using your senses to observe: sight, sound, touch, taste, and smell Observations can include taking measurements and calculations Temp, movement, density……..

Observations - Sampling Sampling - having a small group represent the whole To be useful the sample must be large and random. Why? What happens if the sample is too small? What happens if the sample is not random?

Step #3: Forming a Hypothesis Hypothesis: Educated guess, based on observations, can be tested Prediction: Statement made in advance that states what will be obtained by testing your hypothesis “If - Then” statement

Step #4: Testing the Hypothesis A hypothesis is often tested by an experiment

Controlled Experiment: An experiment in which we only change one variable at a time.  The control group is used as a standard Independent Variable: The variable that causes change from group to group  Manipulated Variable (What we change) Dependent Variable: The variable that changes in response to the independent variable  Responding Variable (What will change) Step #4: Testing the Hypothesis