1 APES Warm Up 9/18/15: Explain the difference between toxic colonialism and environmental racism. Don’t forget to turn in the Viking Mystery worksheet if you haven’t already

2 William P. Cunningham University of Minnesota Mary Ann Cunningham Vassar College Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Chapter 02 Lecture Outline

3 Outline 2.1--What is Science? Variables and Experimental Design 2.2--Models and Systems 2.3--Consensus and Conflict in Science Recognizing Pseudoscience Environmental Science vs. Environmentalism

4 Principles of Science and Systems

5 What is Science? Science is:  a methodical, logical process for gaining knowledge about natural phenomena  a cumulative body of knowledge produced by informed, educated scholars  a process based on careful observation and hypothesis testing  a way for us to explain how the natural world works

6 Empiricism—learn from observations Uniformitarianism- similar patterns & processes continue through time Parsimony— simple explanation is likely correct

7 Uncertainty— explanations change with new evidence Repeatability- should be able to recreate results of experimentation Elusive—absolute proof is not possible Testable— generate hypotheses to test our ideas

8 Science Depends on skepticism and accuracy Ideally scientists are skeptical and unbiased. Scientists strive for:  accuracy - correctness of measurements  reproducibility - repeatability of results (repeating studies or tests is called replication)

9 What is the difference between accuracy and precision? Why are they both important during scientific experimentation?

10 Explain the reasoning behind using Significant Figures: This refers to the level of detail you actually know: You have a ruler that shows centimeters and millimeters, but nothing smaller You make several measurements that average out to be Reporting this figure implies that you are measuring more accurately than your equipment will allow Your average is reported as 6.4 because that’s as accurate as you can get.

11 APES Warm Up 9/21/15: Bob is testing the effect of music on plant growth. He thinks that music makes plants grow faster. What would you use for the following: The control group? The independent variable? The dependent variable? What would he need to see to prove his hypothesis?

12 What are the steps of scientific investigation? Are they always carried out in that exact order?

13 Deductive & Inductive Reasoning Deductive reasoning - logical reasoning from general to specific Inductive reasoning - reasoning from many observations to produce a general rule It is also important to recognize the role of insight, creativity, aesthetics, and luck in research.

14 Hypotheses and Scientific Theories Hypothesis - a testable explanation Null Hypothesis (H 0 ) = states that there is NO effect by the independent variable (the factor you are testing or manipulating)  Helps eliminate bias or expectations.  Example “Eating chocolate does not have an effect on skin clarity” Alternative or Research Hypothesis (H a ) =states the prediction of what happens if the manipulated factor does produce an effect.  Example “If a person eats chocolate then their skin will breakout with pimples” OR “If chocolate causes pimples then the more chocolate a person eats, the more pimples they will have” The Null and Research Hypotheses are opposing statements.

15 Hypotheses and Scientific Theories Scientific theory - a description or explanation that has been supported by a large number of tests and is considered by experts to be reliable EX: The Cell Theory, Theory of Evolution

16 Probability Probability is a measure of how likely something is to occur. Scientists often increase confidence in a study by comparing results to a random sample or a larger group.  Looking to see if these results could have occurred by random (chance) events or if they are significant.

17 Statistics—Important? Many statistical tests focus on calculating the probability that observed results could have occurred by chance (spontaneously, randomly). Usually ecological tests are considered significant if this probability is less than 5% (meaning it could happen by chance too often) The amount of confidence scientists have in the results depends upon the sample size as well. A large sample size is better than a small sample because it is less likely to be influenced by chance or bias.

18 Experimental Designs: 1. Natural experiment - involves observation of events that have already happened 2. Manipulative experiment - conditions are deliberately altered for one variable and all other variables are held constant (such as the B4warmed experiment at the beginning of the chapter)—usually in a lab setting 3. Controlled study - comparing a treatment group (“experimental group”) to a control group which has not received the treatment What is the purpose of a controlled experiment?

19 Why are “blind” and “double blind” experiments performed? Blind experiment - researcher doesn’t know which group has been treated until after the data have been analyzed Double-blind experiment - neither the subject nor the researcher knows who is in the treatment group A placebo may be used—do you know what this is?

20 Variables In each study there is one independent variable and one or more dependent variables. The dependent variable is affected by what happens to the independent variable. In a graph, the dependent (responding) variable is on the vertical (Y) axis and the independent (manipulated) variable is on the horizontal axis (X). REMEMBER: D R Y M I X

21 How are Models useful? Models are simple representations of phenomena. They can be physical models, model organisms, mathematical models, or other types of models. Many fields use models, not just science They allow scientists to study complex systems and predict the effect of conditions that are too difficult to create and control. When multiple models agree, scientists gain confidence.

22 Examples of Scientific Models: Kv4SM Kv4SM Architectural plans Molecular Modeling in Chemistry Toy models—matchbox cars, doll houses Drawings or diagrams

23 End of 2.1—STOP HERE

24 Systems are networks of interdependent components and processes with materials and energy flowing from one component to another. are a central concept in environmental science. examples include ecosystems, climates systems, geologic systems, economic systems

25 Components of a System State Variables store resources such as matter or energy or have the pathways through which these resources move from one state variable to another (the plant and the animals illustrated here in Fig. 2.9 are each state variables).

26 System Characteristics A System can be closed or open.  Closed - self contained, exchanges no matter or energy with the outside  Open – exchanges matter and energy from surroundings Throughput –the energy and matter that flow into, through and out of a system. Positive feedback loop – self perpetuating, as an increase in a state variable leads to further increases in it Negative feedback loop – suppresses change within a system, helps to maintain stability in systems

27 APES Warm Up 9/23/15 Write the following in scientific notation: A) forty five billion B) seven trillion one hundred sixty eight billion C) D) Now add A and B together and simplify

28 Stability of Systems Equilibrium - dynamic state in which system is stable over time (homeostasis) Disturbance - periodic destructive events such as fire or flood Resilience - ability of system to recover quickly from disturbance State Shift –a severe disturbance in which the system does not return to normal but instead results in significant changes in some of its state variables Be sure to know the terms in RED

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31 System Characteristics Emergent properties are characteristics of a whole, functioning system that are quantitatively or qualitatively greater than the sum of each of the system’s parts Beautiful sights and sounds can make a system such as this mountain meadow exciting to study.

32 Consensus and Conflict Scientific consensus (general agreement among informed scholars) stems from a community of scientists who collaborate in a cumulative, self- correcting process. Paradigm shifts (great changes in explanatory frameworks) occur when a majority of scientists agree that an old explanation no longer works very well.

33 Recognizing Pseudoscience

34 Questions: How do politicians and the media affect the public’s interpretation of scientific findings? How might the source of funding for scientific studies, political campaigns, and research reports be important to know when evaluating the validity of information being disseminated? What is the value of peer review in the scientific process?

35 Environmental Science vs. Environmentalism Environmental science is the use of the scientific method to study processes and systems in the environment Environmentalism involves working to influence attitudes and policies that affect our environment

36 Case Study (beg. Of chapter 2) What type of experimental design are they working on? Manipulative, Controlled but in the field (not a lab) What is the Independent Variable, the Dependent Variable, and what are their Constants? IV = ambient (surrounding) temperature DV = CO 2 emission Constants = location (rainfall, sunlight, wildlife, other weather, soil quality)

37 Case Study (beg. Of chapter 2) Their Standard Scientific Steps: Observe & Question—How will forests respond to climate change? Hypothesis—does it give an exact hypothesis in the reading? Procedure—planted a mix of species, randomly chose plots in forest and open areas, exposed plots to 4°C higher, 2°C higher, and ambient temps, and a control with cables and lamps not in use

38 Case Study (beg. Of chapter 2) Their Standard Scientific Steps: Gather Data--measured CO 2 levels in area. Interpret Results— so far CO 2 levels are lower than expected, possibly indicating that the plants adjust their CO 2 output based on temperature

39 Out of Text Reading “Scientific Misconduct is Real, but Rare” The Following Questions should be answered in your Journal—listed as Chapter 2 Article Reflection: What is the motivation for researchers to report false results? According to the article, does it sound like false data is reported often? Support your opinion using calculations. Is there any way that this can be avoided? Does it really matter?