CES 210 1st Edition Lecture 2Environmental Science Lecture TwoWhat is Science?• Science: is a process for producing knowledge both methodically and logically• It depends on scientist making precise observations of natural phenomena• Is a body of knowledge by many scientist• A way for us to explain how our worlds work and meets our practical needsThe Basic Principles of Science• Empiricism: learning about the world through careful observation• Uniformitarianism: basic patterns and process are uniform across time and space• Parisomy: when two plausible explanations are reasonable, the easier one is preferred• Uncertainty: knowledge changes as new evidence appears, and explanations change with the new evidence• Repeatability: test and experiments should be repeatable, if same results cannot be reproduced than the conclusions are incorrect• Proof is elusive: we rarely expect science to prove absolute proof that theory is correct• Testable questions: to find out whether a theory is correct it must be testedSo, why critical thinking?• It identifies the question• Forms a testable hypothesis• Collects data to test the hypothesis• Interpret results: consult prior knowledge (go to bullet one) and if hypothesis is rejected (go to bullet two)• Report for peer review• Publish findingsHypothesis and Scientific Theories• Hypothesis: a testable explanation• Scientific theory: a description of explanation that has been supported by a large number of test and is considered reliable• Our beliefs can never be shown false• If a theory predicts something other than what it was introduced to explain, it is then testable• If it is repeatedly inconsistent then we can believe that it is falseScience depends of Skepticism and Accuracy• Scientists are skeptical and unbiased• They strive for both- Accuracy: correctness of measurements- Reproducibility: repeatability of results (replication: is the repeating of test or studies)These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Experimental Design (5 types)• Natural experiment: involves observation of events that have already happened• Manipulative experiment: some variables are altered while others are held constant• Controlled study: comparing a treatment group to a controlled group (doesn’t receive treatment)• Blind experiment: researcher doesn’t know which group has been altered until after the data has been analyzed• Double-blind experiment: neither the subject or the researcher knows which has received treatment in the groupProbability: measure of how likely something is to occur• Scientist use this to increase confidence in a study by comparing it to a larger groupStatistics: calculating the probability that the observed results could have occurred by chance• Ecological test are considered significant if the probability is less than 5%• Sample size also contributes to scientists confidence is a test (ex: larger sample size = more confidence)Scientific theory: in science, theory is supported by facts when a majority of experts reach a general consensus after a large number of tests• Differs from the general use of theory “unsupported” by factsScience PseudoscienceWillingness to change new evidence Fixed ideasRuthless review No peer reviewTakes accounts of all new discoveriesSelects on favorable discoveriesInvites criticism Sees criticism as conspiracyVerifiable results Non-repeatable resultsLimits claims of usefulness Claims of widespread usefulnessAccurate measurement “ball park” measurmentConsensus and Conflict• Scientific consensus: general agreement among informed scholars (self correcting process)• Paradigm shifts: great changes in an explanatory framework (changing an explanation that is deemed “unsuitable”The Seven Questions1. How reliable are the sources of this particular claim?2. Have these claims been verified by other sources?3. What position does the majority of scientist hold in this issue?4. How does this claim fit with how we know how the world works?5. Are the arguments balanced and logical?6. What do you know about the sources funding for a particular position?7. Where was evidence for competing theories published? (Has is undergone partial reviewor more)Models• Models are used for representation and come in many forms like physical, organism, ormathematical• Allow scientists to study systems that are to complex to see by the naked eye and predictthe effect of conditions that are to difficult to controlSystems• Networks of interdependent components and process, containing materials and energy that flows from one of the component of the system to another. Examples are ecosystems, climate systems, geological systems, economic systems• Are a central concept to environmental scienceComponents of a System• State variable: stores resources such as matter of energy and have pathways that these resources can travel in order to move from one state variable to another. Examples plants to animals• Characteristics: a system can be closed or open- Open: exchanges energy and matter with surroundings- Closed: self contained, changes no matter or energy with the outside- Throughput: the energy and matter that flow in and out of a system- Positive feedback loop: an increase in state creates a further increase in that state- Negative feedback loop: suppresses change within a system, in turn helps maintain stability of a system- Emergent properties: characteristics of a functioning system that are quantitatively or qualitatively greater than the sum of the systems parts. Example sights and sounds can make a system such as a mountain exciting to studyStability of Systems• Equilibrium: system becomes stable over time (homeostasis)• Disturbance: destructive events like a fire or flood that change a system• Resilience: the ability of a system to recover from the disturbance • State shift: a disturbance so severe that the system does not turn back to normal but instead changes some of its state