Introduction to Physical Science Chapter 1

“The world is full of obvious things, which nobody by any chance ever observes.” - Sherlock Holmes

SECTION 1 Scientists use … Observing: Observing: Using one or more of your senses to gather information. Senses? Two types Two types  Qualitative  Quality  Quantitative  Quantity  Examples

Data as Information

Continued How/Where do scientists record data from these two types of observations? ◦ What did you see in the video that could be examples? ◦ Qualitative – ◦ Quantitative –

Continued Inferring – explaining your observations Inferences are based on reasoning from what you already know (prior knowledge ). ◦I◦I nferences made from an observation may be incorrect, even when the inference seems obvious. ◦E◦Example – You know that the ground gets wet when it rains. You go to bed and when you wake up in the morning the ground is wet. You infer that it rained over night.

Continued Predicting – making a forecast of what will happen in the future based on prior knowledge or experience. ◦E◦E xamples:

Observing, Inferring, and Predicting Example When you come home from school you notice a glass of milk on the table and it smells bad. From prior knowledge you know that milk needs to be refrigerated, so you infer that the milk is sour because it was left out of the refrigerator. To make sure your inference is correct you decide to make a test. Before your test you predict (using past experiences and evidence) that if you leave another glass of milk out on the table when you go to school, it will sour by the time you return.

Physical Science is … The study of matter, energy, and the changes they undergo. Divided into two main areas ◦C◦C hemistry ◦P◦P hysics ◦W◦W hat kind of careers involve these two areas?

SECTION 2 Scientific Inquiry What does in mean to inquire? Scientific inquiry refers to the different ways scientists study the natural world. This is an ongoing process.

The Process of Inquiry Scientific inquiry does N OT always occur the same way. The processes that scientists often use are: ◦P◦P osing questions and doing research ◦D◦D eveloping hypotheses ◦D◦D esigning experiments ◦C◦C ollecting and interpreting data ◦D◦D rawing conclusions ◦C◦C ommunicating ideas and results

Continued A question must be able to be answered by scientific inquiry. ◦E◦Experiments or observations A h ypothesis is … ◦T◦T estable ◦I◦I s written as an “If, then” s tatement. ◦I◦I nvestigations must be carried out and evidence gathered to support or disprove hypothesis.

Designing Experiments Variables : factors that can change ◦ First you must examine all the variables ◦ In a well designed experiment only 1 variable is changed ( independent/manipulated ) ◦ The variable that you hope to see a change in is the dependent/responding variable ◦ Controlling an experiment is IMPORTANT!  One variable is changed at a time, all others held constant  This way you can determine is the independent variable is causing the change in the dependent variable.  Example- plants and fertilizer

Collecting and Interpreting Data Data can be qualitative or quantitative Qualitative is recorded as notes in a journal, log, sketch pad, etc. Quantitative is recorded on data tables ◦ Graphs are useful to display quantitative data ◦ Will help to show trends and patterns in the data

Drawing Conclusions and Communication Was my hypothesis answered? How do you communicate results? EXAMPLES?

How Science Develops Models * picture, diagram, computer image, or other physical representation of a of an object or process Theories * Well tested explanation for a variety of observations or experimental results Laws * A statement that describes what scientists expect to happen every time under a particular set of conditions * Would a scientific law that is true in Japan also be true in the United States?

The Nature of Inquiry Page 14 Remember: ◦ There is NO set path that scientific inquiry must take!