Scientific Models and Systems

1. Scientific Models and Systems

2. Objectives Describe how models are used to represent the natural world. Identify four types of scientific models and give examples of each. Identify the benefits and limitations of models. Describe theories and laws. Compare the ways that scientists use hypotheses, theories, and laws. Use models to represent the natural world.

3. What is a Model? A representation of an object, event, idea, or a system is called a model. Models are a graphic representation of an object or an event used to communicate ideas; test predictions; and save time, money, and lives. Models are designed to show the structure or working of an object, system, or concept. A model can help you picture things that are hard to understand or see in your mind.

4. Models�Just the Right Size Models are often used to represent things that are very small or very large. Studying particles of matter that are too small to see with the unaided eye such as cells Studying objects that are too large to see completely, such as Earth or the solar system Models can be used to show items that do not exist or have nor been made yet. Models can show events that happen so slowly or so quickly that we can not normally see the event happen. Studying slow events such as planet rotation Studying fast events such as speed of light

5. Make a Foldable We will make a quad-fold about the four models

6. Four Types of Scientific Models Physical Models Mathematical Models Conceptual (Idea) Models Computer Models

7. Physical Models Physical Models can be seen and touched. Physical models look like the thing they are supposed to represent. Examples (see right) miniature volcanoes the model flower shown at right can be used to learn the parts of a real flower animal cell

8. Mathematical Models Mathematical Models A mathematical model may be made up of numbers, equations, and other forms of data. Examples Charts and graphs Weather maps Punnett square

9. Conceptual (Idea) Models Conceptual Models are systems of ideas or are based on making comparisons with familiar things to explain an idea. Conceptual models are attempt to explain ideas by making comparisons with familiar things to help illustrate or explain the idea. Conceptual models CANNOT be �built�.

10. Computer Models Computer Models are built using computer software Computer models can be seen but not touched Are used for predicting natural events Used in the entertainment industry Examples Computer games Earthquake simulations

11. Design and build a scale model Choose a room in your house or school. Brainstorm ideas for recreating a smaller version (replica). Measure to find the actual dimensions Sketch on paper (graph paper may come in handy) Construct your model. DO NOT GO OVERBOARD with this assignment�it should be able to fit on your lap for a bus ride.

12. Building Scientific Knowledge Scientific Theories An explanation that ties together many related observations, facts, and tested hypotheses is called a theory. Scientific Laws A scientific law is a statement of what will happen in a specific situation. A law tells you how things work. Scientific Change If new evidence challenges an accepted idea, scientists must reexamine the old evidence and reevaluate the old idea.

13. Models Used in Scientific Theories Models are often used to help illustrate and explain scientific theories. A scientific theory is an explanation or model about the behavior of something in nature backed by results obtained from many tests or experiments Theories and models can change as new observations are made. If data gathered over a long period of time supports a hypothesis, scientists become convinced that the hypothesis is useful.

14. Models Prove Scientific Laws A scientific law is a rule that describes a pattern or behavior of something in nature. Scientific Laws are created when a theory and its models correctly predict the results of many different experiments. Laws tell you only what happens, not why it happens. In science, a law is a summary of many experimental results and observations repeated over a lengthy period of time. Laws are not the same as theories. A law tells how things work.

15. Models Limited by current technologies Limited by current information Limited by creator NOT Perfect Safer and cheaper to use than the real thing Test predictions Communicate ideas Not limited to science

16. Instruction Manuals HOMEWORK ASSIGNMENT- due tomorrow Find an instruction manual you can bring to school. Talk with a family member about the communication between the manufacturer and the consumer. Brainstorm ideas for ways to make the manual more clear and easier to use. Create a �teenager manual� for an item you use everyday�like your game systems, DVD, etc. Bring the manual, brainstorm ideas, and teenager manual with you tomorrow. We WILL use these in class!!

17. Systems in Science A system is a group of structures, cycles, and processes that are related to each other, interact, and work together Systems are everywhere not just science (ex school) All systems are made up of other systems (ex human body) Scientist often solve problems by studying just one part of the system.