The Scientific Method …and the Nature of Science

What is science? Science is the total collection of knowledge gained by observation of the physical universe. Science is the total collection of knowledge gained by observation of the physical universe. It tries to answer the questions "how" and "why." It tries to answer the questions "how" and "why." It is a logical way of problem solving. It is a logical way of problem solving. It is basically common sense. It is basically common sense.

The Scientific World View The world is understandable - truth exists Scientific theories are subject to change Science cannot provide answers to all questions

Characteristics of Science Science is a process Scientific theories must be falsifiable Scientific theories must be able to predict Scientific experiments must be repeatable Confidence in theories is not absolute

The Limitations of Science Cannot make value judgments. Cannot make value judgments. Cannot prove something doesn't exist (universal negative). Cannot prove something doesn't exist (universal negative). Scientific investigation is as limited as the instruments we use. Scientific investigation is as limited as the instruments we use.

Inductive and Deductive Approaches Inductive Approach Inductive Approach Empirical data leads to generalization Empirical data leads to generalization Experiments or observations lead to predictions about the future Experiments or observations lead to predictions about the future Used by scientists trying to discover or explain phenomena Used by scientists trying to discover or explain phenomena Deductive Approach Deductive Approach Observations lead to explanations about past events or observed phenomena Observations lead to explanations about past events or observed phenomena Post-dictions can be tested with experiments Post-dictions can be tested with experiments Used by Police and CSI specialists Used by Police and CSI specialists

Inductive Approach Example Empirical Data Empirical Data The more times I water my grass during the week, the greener the grass becomes The more times I water my grass during the week, the greener the grass becomes Generalization Generalization More water equals greener grass More water equals greener grass This yields correlation only This yields correlation only not cause and effect not cause and effect

Deductive Approach Example General idea More water equals greener grass Prediction The more I water, the greener the grass will become Experiment Vary the amount of water and measure how green the grass becomes

Scientific Statements Facts - things that are observable and indisputable. Facts - things that are observable and indisputable. Data - any piece of information; usually gained through experimentation. Data - any piece of information; usually gained through experimentation. Theories - explanations usually based on evidence (may be wrong). Theories - explanations usually based on evidence (may be wrong). Models - man-made ideas to help us visualize scientific concepts. Models - man-made ideas to help us visualize scientific concepts. Laws - statements that describe patterns in nature with no known exceptions. Laws - statements that describe patterns in nature with no known exceptions.

The Scientific Method Observe the situation Observe the situation Ask a question Ask a question Turn that question into a testable idea Turn that question into a testable idea Predict the outcome of your experiment Predict the outcome of your experiment Perform your experiment Perform your experiment Analyze the results Analyze the results Evaluate your idea or hypothesis Evaluate your idea or hypothesis

Systems of Measurement English System of Measurement: is the one you use commonly, and includes pounds, feet, and gallons. English System of Measurement: is the one you use commonly, and includes pounds, feet, and gallons. International System of Measurement or SI: is called the metric system in the US. It’s based on units of ten, and all science measurements use this system. International System of Measurement or SI: is called the metric system in the US. It’s based on units of ten, and all science measurements use this system. Know these SI units: Know these SI units: Meter - unit of length (about a yard) Meter - unit of length (about a yard) Kilogram - unit of mass (about ½ a pound) Kilogram - unit of mass (about ½ a pound) Liter - unit of volume (about a quart) Liter - unit of volume (about a quart) Celsius Degrees - temperature unit (about ½ degree F°) Celsius Degrees - temperature unit (about ½ degree F°) Second - unit of time ( same unit in metric, subdivides by tenths ) Second - unit of time ( same unit in metric, subdivides by tenths )

It’s All Greek to Me! Mono - 1 Mono - 1 Duo/Di - 2 Duo/Di - 2 Tri - 3 Tri - 3 Tetra - 4 Tetra - 4 Penta - 5 Penta - 5 Hex/Hexa - 6 Hex/Hexa - 6 Hepta - 7 Hepta - 7 Octa - 8 Octa - 8 Deca - 10 Deca - 10 Hecaton 100 Hecaton 100

Friends, Romans, Countrymen! 1 - una 1 - una 2 - duo 2 - duo 3 - tres, tria 3 - tres, tria 4 - quattuor 4 - quattuor 5 - quinque 5 - quinque 6 - sex 6 - sex 7 - septem7 - septem 8 - octo8 - octo 9 - novem9 - novem 10 - decem10 - decem centum100 - centum mille mille