Transcript Chapter 2
Warm UP Write down what you remember about the steps of the scientific method…. Then….Check your book to clarify the steps Tools of Environmental Science Chapter 2.1 The Experimental Method • Set of steps scientists use to conduct experiments • Observation • Hypothesis • educated guess – Stated in an IF /THEN statement) • Experiment • Collect & Analyze data • Conclusion • Repeat The Experimental Method Vocabulary • Experiment • Procedure designed to test a hypothesis under controlled conditions • Variable • Factor of interest (what you are studying) •Ex. Phosphate levels in Shenandoah River possibly causing fish kills • Independent Variable –what “I” change in an experiment • Dependent Variable –Data that is collected • Experimental Group • Group in an experiment that receives treatment The Experimental Method Vocabulary • Control Group • Group that doesn’t receive treatment (used for comparison) • Constants • What is kept constant or the same in an experiment The Correlation Method • Used when cannot physically do an experiment • Example: What was earth’s climate like 60 million years ago?????? • Scientists test predictions by examining “correlations” or reliable associations between two or more events • Example: Tree rings and Jamestown settlers. • Not full-proof though It’s Time to Start Class! Warm UP When is the correlation method used in science? Airplane Lab Time to practice the scientific method…… YOU and a partner will build a paper airplane………. Warm UP What is the dependent variable in your experiment? Warm UP - Feb. 11th What is the variable that you change in an experiment? Tools of Environmental Science Chapter 2.2 Statistics and models Statistics Collection and classification of data that are in the form of numbers How do scientists use statistics? Describe populations Find averages Mean – number obtained by adding up the datat for a given characteristic and dividing this sum by the number of individuals Sample – group of individuals selected to represent population Finding DISTRIBUTION Relative arrangement of the members of a statistical population. Find PROBABILITY Chance that something will happen Examples Average Test grades: 70, 55, 85, 82, 99, 73 = 464/6 = 77.3 (average) Distribution Probability Penny toss What is the chance it would come up heads? Statistics in the News • The STATS study polled nearly 500 randomly selected members of the American Meteorological Society and the American Geophysical Union listed in American Men and Women of Science, the longtime "Who's Who" directory of the scientific community…..84% believe "human-induced greenhouse warming" is now occurring, compared with only 5% who reject this conclusion. And 74% say the "currently available scientific evidence substantiates" its occurrence, while only 9% disagree Thinking about Risks….. • In scientific terms, RISK: • Probability of an unwanted outcome. • EXAMPLE: • If you have a 1 in 4 chance of failing class, the risk is ¼ or 0.25. • High Risk • Ozone depletion • Global climate change • Getting injured/dying in a car accident • Low Risk • Oil spills (WOW….well, low doesn’t mean NO) • Radioactive contamination • Getting injured/dying in a plane crash Models • Models are patterns, plans, representations, or descriptions designed to show the structure or workings of an object, system or concept. • Scientists use several different types of models to help them learn about our environment. Physical Models • Physical models are three-dimensional models you can touch. • Their most important feature is that they closely resemble the object or system they represent, although they may be larger or smaller. • The most useful models teach scientists something new and help to further other discoveries. Physical Models • One of the most famous physical models was used to discover the structure of DNA. • The structural model was built based on the size, shape, and bonding qualities of DNA. • The pieces of the model put together helped the scientist figure out the potential structure of DNA. • Discovering the structure led the the understanding of DNA replication. Graphical Models • Maps and charts are the most common examples of graphical models. • Scientists use graphical models to show things such as the position of the starts, the amount of forest cover in a given area, and the depth of the water in a river or along a coast. Conceptual Models cont. Conceptual models are verbal or graphical explanations for how a system work or is organized. A flow-chart diagram is an example of a conceptual model. A flow-chart uses boxes linked by arrows to illustrate what a system contains, how those contents are organized, and how they affect one another. Concpetual Model Conceptual models can also be verbal descriptions or even drawings. For example, one conceptual model of the structure of an atom describes the atom as one large ball being circled by several smaller balls. This illustrates another point, that a model can be more than one type. An atomic model made using plastic balls is both a conceptual and physical model. Warm UP – Feb. 13th Maps and charts are the most common examples of _____________models. Mathematical Models • Mathematical models are one or more equations that represent the way system or process works. • Mathematical models are especially useful in cases with many variables, such as the many things that affect the weather. Mathematical Models • Although mathematical models use number and equations, they are not always right. • People are the ones who interpret the data and write the equations. So, if the data or the equations are wrong, the model will not be realistic and will provide incorrect information. • Like all models, mathematical models are only as good as the data that went into building them. Mathematical Models cont. • Scientists use mathematical models to create amazing, as well as useful images. • “False color” satellite images are created using mathematical models. • Scientists use the models to relate the amount of energy reflected from objects to the objects’ physical condition. Values and the Environment • Scientific research is an essential first step in solving environmental problems. • However, before research can begin, an examination of values is usually needed. • Values are principles or standards that an individual considers to be important. • There are many values that affect environmental decision making. Values that affect Environmental Decision Making An Environmental Decision – Making Model • A decision-making model is a conceptual model that provides a systematic process for making decisions. • Decision-making models can be used to help you make decisions about environmental issues which can be very difficult. The first step in the model is to gather information. This includes things such as watching news reports, and talking to experts. Second, consider which values apply to the issue. Next, explore the consequences of each option. Finally, evaluate all of the information and make a decision. Lets apply this to a local issues • FISH KILLS IN THE SHENANDOAH RIVER Fish Kill Background Video • http://www.youtube.com/watch?v=MDT JyY0gRmQ • http://www.msnbc.msn.com/id/211345 40/vp/34483066#34483066 • http://www.pbs.org/wgbh/pages/frontli ne/poisonedwaters/view/ Field Activity We will go outside to create a conceptual model of what you see….. YOU WILL NEED… 1. Paper 2. Pencil 3. Textbook Pick one item found in nature to observe and write down all the components that interact with it. You can make it a flow chart, diagram, etc…. Warm Up – Tues. Feb. 18th What would happen if the frog was driven to extinction?