Big Idea 3 : The Role of Theories, Laws, Hypotheses, and Models Description :  The terms that describe examples of scientific knowledge, for example; "theory," "law," "hypothesis," and "model" have very specific meanings and functions within science.

Benchmark Number & Descriptor SC.6.N.3.1 Recognize and explain that a scientific theory is a well-supported and widely accepted explanation of nature and is not simply a claim posed by an individual.   Thus, the use of the term theory in science is very different than how it is used in everyday life. SC.6.N.3.2 Recognize and explain that a scientific law is a description of a specific relationship under given conditions in the natural world. Thus, scientific laws are different from societal laws. SC.6.N.3.3 Give several examples of scientific laws. SC.6.N.3.4 Identify the role of models in the context of the sixth grade science benchmarks.

WHAT’s a theory?

SCIENTIFIC THEORY A scientific explanation to a pattern in the natural world Many observations and much evidence is needed in order to create a valid theory. Scientific investigation is a key part when creating theories. Theories may be supported by scientific evidence but may be incorrect. Evidence may change with time; better technology Example: Geocentric (earth in middle of solar system) to Heliocentric model (sun in middle of solar system)

SCIENTIFIC THEORY Listed below are some examples of Science Theories: 1. Modern Atomic Theory 2. Kinetic Molecular Theory 3. The Germ Theory of Disease 4. The Big Bang Theory 5. The Theory of Evolution 6. The Theory of Gravity 7. Cell Theory The Theories of Relativity 9. Plate Tectonic Theory 10. Quantum Mechanical Theory 11. String Theory 12. Unified Field Theory

SCIENCE THEORY SCIENCE EVERYDAY VS. Not a guess, hunch, hypothesis, or speculation. Based on the hypotheses and evidence All knowledge must have peer review and verification. Is a point of view Is a belief system Theory may vary among the different cultures. Accepted knowledge does not need peer review or verification.

KNOWLEDGE CHECK What is a Scientific Theory? Give an example of a Scientific Theory which has changed over time. What is the difference between a Scientific Theory and an Everyday Theory? Give an example of both.

KNOWLEDGE CHECK What is a Scientific Theory? A scientific explanation to a pattern in the natural world Give an example of a Scientific Theory which has changed over time. Arrangement of the solar system (geocentric to heliocentric) What is the difference between a Scientific Theory and an Everyday Theory? Give an example of both. Science – based on experimentation and research (Example: Newton’s Laws of Motion); Everyday – based on thought and opinion (Example: Who may have committed a robbery).

WHO MADE THAT LAW?

LAW OF NATURE Based on nature Countless experiments have been done to prove a natural phenomenon. Laws of Nature have validity everywhere. Laws of Nature can be changed without penalty if new information presented. EXAMPLES OF LAWS OF NATURE: Newton’s Laws of Motion Relativity Theory Universal Law of Gravity

LAW OF SOCIETY EXAMPLES OF LAWS OF SOCIETY: Laws of Society are legislated. They are agreed upon and enforced If evidence is presented which shows the law has been broken, you are punished. Laws of Society can be changed or repealed. EXAMPLES OF LAWS OF SOCIETY: Judicial System is based upon Laws of Society Speed limits Amendments

KNOWLEDGE CHECK Describe the difference between a Law of Nature and a Law of Society. Give an example of each. “What goes up, must come down.” Is this a law of Nature or Society? Why?

KNOWLEDGE CHECK Describe the difference between a Law of Nature and a Law of Society. Give an example of each. Law of Nature is based on things which occur in nature. Example: Universal Law of Gravity. Law of Society is man-made and can be enforced with a penalty. Example: Speed limits, if you break them, there is a consequence, such as a ticket. “What goes up, must come down.” Is this a law of Nature or Society? Why? Law of Nature. Gravity is found in the environment; it is not man-made.

WHAT’S IN A MODEL?

MODELS Models are a visual representation that help scientists study something in more depth. Models can be used for the following: Study objects that are too small to see Study objects that are too large to see Help explain the past and the present Help predict the future There are 2 general types of models: Physical Mathematical

MODELS PHYSICAL EXAMPLES Model of an atom Periodic Table of Elements Models that you can touch Representation of an item they want to study Models may have some limitations. Because we may not see an actual picture, models are thoughts and ideas from our heads. Scaling of ideas A flat wall map has a different scaling then a round globe. Model of an atom Periodic Table of Elements Punnett Squares Magnets Solar System Crash-Test Dummies

MODELS MATHEMATICAL EXAMPLES Force = Mass x Acceleration Made up of math equations and data They allow you to calculate things. Some calculations are very simple and utilize simple equations. Some calculations are very complex ,and computers are needed to find the answer. Graphs can be made from mathematical calculations. These graphs help put numbers/data into a visual representation. Force = Mass x Acceleration Speed = Distance/Time Kinetic Energy = ½ Mass x Velocity Density = Mass/Volume

KNOWLEDGE CHECK List 3 reasons why scientists use models. What are the two main types of scientific models? Give an example of each model and a downfall for each.

KNOWLEDGE CHECK List 3 reasons why scientists use models. To see some items which are too small; help predict the future; help represent the past. What are the two main types of scientific models? Physical and Mathematical Give an example of each model and a downfall for each. Physical: Map, downfall the distances are different on a globe then on a map; Mathematical: Force = mass x acceleration, downfall a computer may be relied upon to calculate the answer.