Critical Thinking: Science, Models, and Systems

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Critical Thinking Science, Models, and Systems
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What Is Science?

• Science is a pursuit of knowledge about how the
  world works
• Scientific data is collected by making
  observations and taking measurements
• Observations involve the five senses, and help
  answer questions or problems

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Observation

• Qualitative
• of, relating to, or involving quality or kind
• Quantitative
• of, relating to, or involving the measurement of
  quantity or amount

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• Quantitative
• 700 nm wavelength
• 300 million light years
• Smaller than 1 um
• Burns candle at 1 cm per minute
• 350 degrees C

• Qualitative
• Red
• Far from the earth
• Microscopic
• Burns quickly
• Hot

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Inference

• To conclude from evidence or premises
• To reason from circumstance surmise We can
  infer that his motive in publishing the diary was
  less than honorable
• To lead to as a consequence or conclusion
  Socrates argued that a statue inferred the
  existence of a sculptor

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Vocabulary

• Experiment
• A procedure to study a phenomenon under known
  conditions
• Must have a Control
• Hypotheses
• A possible explanation of something observed in
  nature.
• Model
• An approximate representation of a system being
  studied.

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Theory and Law

• Scientific Theory
• A hypothesis that has been supported by multiple
  scientists experiments in multiple locations
• A Scientific Law
• a description of what we find happening in nature
  over and over again in a certain way

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Scientific Laws

• Law of Conservation of Matter
• Matter can be changed from one form to another,
  but never created or destroyed.
• Atomic Theory of Matter
• All matter is made of atoms which cannot be
  destroyed, created, or subdivided.

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Accuracy and Precision

• Accuracy
• The extent to which a measurement agrees with the
  accepted or correct value for that quantity.
• Precision
• A measure of reproducibility, or how closely a
  series of measurements of the same quantity
  agrees with one another.

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Reasoning

• Inductive Reasoning
• Uses observations and facts to arrive at
  hypotheses
• All mammals breathe oxygen.
• Deductive Reasoning
• Uses logic to arrive at a specific conclusion
  based on a generalization
• All birds have feathers, Eagles are birds,
  therefore All eagles have feathers.

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Scientific Methods

• What is the question to be answered?
• What relevant facts and data are known?
• What new data should be collected?
• After collection, can it be used to make a law?
• What hypothesis can be invented to explain this?
  How can it become a theory?

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Experiments

• Variables are what affect processes in the
  experiment.
• Controlled experiments have only one variable
• Experimental group gets the variable
• Control group does not have the variable
• Placebo is a harmless pill that resembles the
  pill being tested.
• In double blind experiments, neither the patient
  nor the doctors know who is the control or
  experiment group.

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Frontier and Consensus Science

• Frontier Science
• Scientific breakthroughs and controversial data
  that has not been widely tested or accepted
• String Theory
• Consensus or Applied Science
• Consists of data, theories, and laws that are
  widely accepted by scientists considered experts
  in the field involved
• Human Genome Project

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Systems

• A system is a set of components that function and
  interact in some regular and predictable manner
• It has a structure and a function
• The earth is a closed system for matter and
  an open system for energy

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http//asd-www.larc.nasa.gov/erbe/components2.gif
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http//www.bio.miami.edu/dana/160/watercycle.gif
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Scientific Models - Mental

• Mental models help people perceive the world,
  control their bodies and think
• Working model of a car engine while you are
  trying to diagnose a problem

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Conceptual Models

• Describes general relationships among components
  of a system.

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Graphic Models

• Compile and display data in meaningful patterns.

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Physical Models

• Miniature versions of large systems that are made
  to test out designs and ideas.

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Mathematical Model

• Consists of one or more mathematical equations to
  describe the behavior of a system.

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Feedback Loops

• A feedback loop occurs when an output of a system
  is fed back as an input
• Two kinds of feedback loops
• Positive
• Negative

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Feedback Loops

• Positive loops are runaway cycles where a change
  in a certain direction causes further change in
  the same direction
• Melting of permafrost will release methane which
  will accelerate global warming
• Negative loops occur when a change in a certain
  direction leads to a lessening of that change
• Moose and wolves

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Synergy and Chaos

• Synergy occurs when two or more processes
  interact so the combined effect is greater than
  the sum of the separate effects
• Systems at each level affect other levels
• The whole is greater than the sum of its parts
• Ex. ecology forests
• Chaos occurs in a system when there is no pattern
  and it never repeats itself
• Noise versus Music

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Environmental Ethics

• Ethics the study of good and bad, right and
  wrong
• Ethical standards criteria that help
  differentiate right from wrong
• Environmental ethics the study of ethical
  questions regarding human interactions with the
  environment

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Early Environmental Ethics

• The roots of environmental ethics are ancient.
• The modern urge for environmental protection grew
  with problems spawned by the industrial
  revolution.

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Early Environmental Philosophers

• The industrial revolution inspired reaction.
• John Ruskin Criticized polluted 19th-century
  cities, and desacralizing nature.
• Ralph Waldo Emerson and Henry David Thoreau
  Transcendentalists viewed nature as divine, and
  opposed materialism.

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The Preservation Ethic

• John Muir (right, with President Roosevelt at
  Yosemite) advocated preserving unspoiled nature,
  for its own sake and for human fulfillment.

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The Conservation Ethic

• Gifford Pinchot advocated using natural
  resources, but exploiting them wisely, for the
  greatest good for the greatest number for the
  longest time.

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The Land Ethic

• Aldo Leopold urged people to view themselves as
  part of nature, and to strive to maintain the
  integrity, stability, and beauty of the biotic
  community.

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QUESTION Review

• An anthropocentric worldview would consider the
  impact of an action on ?
• a. Humans only
• b. Animals only
• c. Plants only
• d. All living things
• e. All nonliving things

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QUESTION Review

• Which ethic holds that people should use
  resources for the greatest good for the greatest
  number for the longest time?
• a. Preservation ethic
• b. Land ethic
• c. Conservation ethic
• d. Deep ecology
• e. Biocentrism

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QUESTION Review

• Which is NOT an assumption of neoclassical
  economics that can lead to environmental
  degradation?
• a. Resources are unlimited.
• b. Resources are limited.
• c. Long-term effects are downplayed.
• d. All costs and benefits are experienced by the
  buyer and seller alone.
• e. Growth is good.

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QUESTION Review

• Which is an ecosystem service?
• a. Water purification in the atmosphere
• b. Crop pollination by insects
• c. Nutrient cycling in ecosystems
• d. Waste treatment by bacteria
• e. All of the above

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QUESTION Weighing the Issues

• Which worldview is closest to your own?
• a. Anthropocentric
• b. Biocentric
• c. Ecocentric

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QUESTION Weighing the Issues

• Should economists try to assign monetary amounts
  to nonmarket values such as aesthetic,
  cultural, and existence values?
• a. Yes, because this draws attention to the
  importance of these values.
• b. No, because the amounts can never be made
  objective and exact.

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QUESTION Interpreting Graphs and Data

• In conventional economic theory,
• the price of a good is set?

a. Primarily by supply b. Primarily by
demand c. By demand when quantity is low and
supply when quantity is high d. By the point at
which demand equals supply
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QUESTION Interpreting Graphs and Data

• Why is GPI less than GDP (red arrow) in this
  example?

a. Environmental, social, and economic costs are
greater than benefits ignored by GDP. b.
Environmental costs are greater than social
costs. c. GPI is always lower than GDP.
From The Science behind the Stories
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QUESTION Viewpoints

• From what you have seen in your lifetime, do you
  feel that poor or minority communities receive
  protection from pollution and other environmental
  threats equal to that received by wealthy
  communities?
• a. Yes, in law and in practice.
• b. In law but not in practice.
• c. No, not in law or in practice.