The Role of Theories, Laws, Hypotheses, and Models

WHAT is 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 Modern Atomic Theory The Big Bang Theory Listed below are some examples of Science Theories: Modern Atomic Theory The Big Bang Theory The Theory of Evolution The Theory of Gravity Cell Theory Plate Tectonic 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.

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).

LAWs in Science

Scientific Laws Based on nature; referred to as “Laws of Nature” Countless experiments have been done to prove a natural phenomenon. Laws of Nature have validity everywhere Laws of Nature can not usually be changed EXAMPLES OF LAWS OF NATURE: Newton’s Laws of Motion Law of the Conservation of Matter

Scientific MODELs

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

MODELS PHYSICAL EXAMPLES 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. EXAMPLES Model of an atom Solar System Crash-Test Dummies

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.