THE NATURE OF SCIENCE Scientific Method When scientists

THE NATURE OF SCIENCE

Scientific Method • When scientists try to solve a mystery they use a problemsolving procedure called the scientific method • The six steps to the scientific method are 1. 2. 3. 4. 5. 6. Identify the problem Gather information Develop a hypothesis Test the hypothesis Analyze the results Draw a conclusion

Science • Science means “having knowledge” • Science is a process of observing, studying, and thinking about things in your world to gain knowledge

Earth Science • Science is divided into different areas of study • The kind of science you will study this year is Earth Science

Earth Science • Some Earth science topics include: • Geology - The study of Earth and its matter, processes, and history • Meteorology – The study of Earths weather and the forces that cause it • Oceanography – The study of Earth’s oceans, their processes, and life within them • Astronomy – The study of objects in space, including stars, planets, comets, and their origins

Science • Much of the information you will learn about has been discovered over the ages by people who conducted scientific tests • Many unanswered questions remain and much more is waiting to be discovered

Testing and Experimentation • Experimenting is an important part of science • For an experiment to be effective it must be carefully designed

Experiment Example • Suppose you want to know which brand of dishwashing liquid cleans dishes best. • First you would need to research dishwashing liquids, as you research you may make an educated guess of which brand works best, this is a hypothesis. • Next you would design an experiment that tests the validity of your hypothesis

Experiment Example • You will have to consider which brands you will test, the amount of soap, type and number of dishes, how much and what type of grease is on the dishes, amount and temperature of water, and type of sponge or washcloth used. • All these factors could affect the outcome of the experiment.

Variables and Constants • The different factors that can change in an experiment are variables • You can only test one variable at a time for accurate results • A variable that you change is the independent variable • In our example the brand of dishwashing liquid is the independent variable

Variables and Constants • Constants are variables that do not change in an experiment • Constants in our example would include, the amount of dishwashing liquid, the amount and type of water used, the type of grease, and the temperature of the water

Variables and Constants • A dependent variable is the variable being measured • In our example experiment the amount of grease left on the dishes after washing would be the dependent variable

Controls • A control is a standard to which your results can be compared • A control for our example would be washing the dishes in only hot water with no dishwashing soap

Repeating Experiments • For your results to be valid your tests should be repeated many times to see whether you can confirm your original results. • If you can show the same results in 100 trials under the same conditions, then you have a conclusion you can feel confident about

Data • During the experiment you should observe what is happening and carefully record your data in a table • Be sure to include any unexpected results in your data, many discoveries have been made when experiments produced unexpected results

Hypothesis • A hypothesis is an educated guess • Scientists test hypotheses using experiments • If data gathered over a long period of time support a hypothesis, the hypothesis may eventually become a theory

Theory • A scientific theory is an explanation or model backed by results obtained from many tests or experiments • Before a hypothesis can become a theory it must be subjected to many years of tests and observations

Scientific Law • Scientific law is a rule that describes the behavior of something in nature • Usually a scientific law describes what will happen in a given situation but doesn’t explain why it happened

Ethics • Science is limited in what it can explain • For a problem to be scientifically studied, there must be variables that can be observed, measured, and tested • Problems dealing with ethics and belief systems cannot be answered using these methods