What is Science? Science refers to a method of learning about the natural world, as well as to the knowledge gained through that process. Scientific Inquiry refers to the diverse ways in which we try to answer questions and solve problems concerning the natural world. Observation: using the five senses to gather information. Inference: an interpretation based upon our observations.

Science is Always Evolving (Changing)! Science changes as we acquire new information…and that makes sense! Doesn’t it? At one time it was a fact that Earth was flat. We’ve learned some stuff since then. This is why it is more accurate to use the terms supported or refuted rather than true or false.

Objective Statement: a statement of fact. The game lasted three hours. Subjective Statement: a statement of opinion. The game lasted too long! Science is objective by nature.

Qualitative vs. Quantitative Describes QUALITIES… Purple Acrid Salty Describes QUANTITY 14.745 cm 55 square meters 4 x 104 A.U.

Develop a hypothesis (If/Then). Experimenting and testing. The Scientific Method Ask a question. Develop a hypothesis (If/Then). Experimenting and testing. Collect and organize data. Analyze data. Draw conclusions (substantiate or refute). Retest.

A Hypothesis: a possible explanation for observations relating to a scientific question. A hypothesis makes a prediction! Hypotheses are tested by conducting controlled experiments. In this type of experiment, scientists determine how one particular variable affects the outcome.

A Valid Scientific Hypothesis Must Be Testable! If you can’t design an experiment to test a hypothesis…it’s not useful. If you develop a hypothesis, test it, and it’s not supported…that’s OK! You’ve still learned from it. We test hypotheses using controlled experiments.

Variable: a factor that can change in an experiment Variable: a factor that can change in an experiment. There are three types…but you knew that right  Manipulated or Independent Variable: changed by the scientist (dats you!). You only want ONE of these! Responding or Dependent Variable: changes because of the manipulated variable. Controlled Variables: These stay the same during an experiment. Data are the facts figures and other evidence gained through observation

Variables Manipulated or Independent Variable changed or controlled by the scientist. Example: The amount of water (in ml) given to a plant daily. Responding or Dependent Variable changes because of the manipulated variable. Example: The measured daily growth of the plant (in cm).

What is true of a valid scientific hypothesis? Test Yourself! Why don’t we want to have more than one manipulated/independent variable in a controlled experiment? What is true of a valid scientific hypothesis? Design an experiment and list your manipulated, responding, and controlled variables.

Scientific Theory A theory is NOT the same as a hypothesis. You’d be amazed at how many folks don’t understand that…you will not be one of those folks! A theory is an explanation for a set of related observations or events based upon proven hypotheses. It’s verified over and over by detached groups of researchers (WELL-TESTED). In other words…it has been subjected to rigorous testing…everywhere…and the evidence always supports it! One scientist cannot create a theory; he/she can only develop a hypothesis.

In general, both a scientific theory and a scientific law are accepted to be “true” by the scientific community as a whole. Both are used to make predictions of events.

Theory v Law Ok…it’s like this…a theory ties together (it’s unifying) many related facts, observations, supported hypotheses. It EXPLAINS WHY THINGS HAPPEN, and allows us to make predictions. A Law also ties this type of information together, and allows us to make predictions, BUT…IT DOES NOT EXPLAIN WHY?

Check Your Head (Take a moment and answer these in your notebook.) Why is it inaccurate to say that a scientific theory is “just a theory?” Can one scientist develop a theory on his/her own? Explain please!

Scientific Models Representations of objects or systems 1st Type: Physical- An actual 3-D imitation that can be studied. Limitation: Not exactly like the real thing…for example…a plastic model of a temperate forest doesn’t actually have living inhabitants that interact.

Physical Model

2nd Type: Mathematical-Numbers, Data, Equations…if you have certain data, you can “plug it into” the model and make PREDICTIONS. Limitation: It still isn’t the actual event…it’s a prediction and predictions can be wrong.

Mathematical Model

3rd Type: Conceptual-qualitative models that help to diagram important interrelationships among processes and systems that we study. Limitation: Again…not the real thing…but helps us understand the real thing.

Conceptual Model