What is Science?

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What is Science?

• Science refers to a method of learning about the
  natural world, as well as to the knowledge
  gained through that process.
• Scientific Inquiry refers to the diverse ways in
  which we try to answer questions and solve
  problems concerning the natural world.
• Observation using the five senses to gather
  information.
• Inference an interpretation based upon our
  observations.

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Science is Always Evolving (Changing)!

• Science changes as we acquire new informationand
  that makes sense! Doesnt it?
• At one time it was a fact that Earth was flat.
  Weve learned some stuff since then.
• This is why it is more accurate to use the terms
  supported or refuted rather than true or false.

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• Objective Statement a statement of fact.
• The game lasted three hours.
• Subjective Statement a statement of opinion.
• The game lasted too long!
• Science is objective by nature.

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Qualitative vs. Quantitative
Qualitative Quantitative
Describes QUALITIES Purple Acrid Salty Describes QUANTITY 14.745 cm 55 square meters 4 x 104 A.U.
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• The Scientific Method
• Ask a question.
• Develop a hypothesis (If/Then).
• Experimenting and testing.
• Collect and organize data.
• Analyze data.
• Draw conclusions (substantiate or refute).
• Retest.

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• A Hypothesis a possible explanation for
  observations relating to a scientific question.
• A hypothesis makes a prediction!
• Hypotheses are tested by conducting controlled
  experiments. In this type of experiment,
  scientists determine how one particular variable
  affects the outcome.

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A Valid Scientific Hypothesis Must Be Testable!

• If you cant design an experiment to test a
  hypothesisits not useful.
• If you develop a hypothesis, test it, and its
  not supportedthats OK! Youve still learned
  from it.
• We test hypotheses using controlled experiments.

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• Variable a factor that can change in an
  experiment. There are three typesbut you knew
  that right ?
• Manipulated or Independent Variable changed by
  the scientist (dats you!). You only want ONE of
  these!
• Responding or Dependent Variable changes because
  of the manipulated variable.
• Controlled Variables These stay the same during
  an experiment.
• Data are the facts figures and other evidence
  gained through observation

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Variables

• Manipulated or Independent Variable
• changed or controlled by the scientist.
• Example The amount of water (in ml) given to a
  plant daily.

• Responding or Dependent Variable
• changes because of the manipulated variable.
• Example The measured daily growth of the plant
  (in cm).

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• Test Yourself!
• Why dont we want to have more than one
  manipulated/independent variable in a controlled
  experiment?
• What is true of a valid scientific hypothesis?
• Design an experiment and list your manipulated,
  responding, and controlled variables.

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Scientific Theory

• A theory is NOT the same as a hypothesis. Youd
  be amazed at how many folks dont understand
  thatyou will not be one of those folks!
• A theory is an explanation for a set of related
  observations or events based upon proven
  hypotheses.
• Its verified over and over by detached groups
  of researchers (WELL-TESTED).
• In other wordsit has been subjected to rigorous
  testingeverywhereand the evidence always
  supports it!
• One scientist cannot create a theory he/she can
  only develop a hypothesis.

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• In general, both a scientific theory and a
  scientific law are accepted to be true by the
  scientific community as a whole. Both are used to
  make predictions of events.

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Theory v Law

• Okits like thisa theory ties together (its
  unifying) many related facts, observations,
  supported hypotheses. It EXPLAINS WHY THINGS
  HAPPEN, and allows us to make predictions.
• A Law also ties this type of information
  together, and allows us to make predictions,
  BUTIT DOES NOT EXPLAIN WHY?

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Check Your Head(Take a moment and answer these
in your notebook.)

1. Why is it inaccurate to say that a scientific
   theory is just a theory?
2. Can one scientist develop a theory on his/her
   own? Explain please!

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Scientific ModelsRepresentations of objects or
systems

• 1st Type Physical- An actual 3-D imitation that
  can be studied.
• Limitation Not exactly like the real thingfor
  examplea plastic model of a temperate forest
  doesnt actually have living inhabitants that
  interact.

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Physical Model
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• 2nd Type Mathematical-Numbers, Data,
  Equationsif you have certain data, you can plug
  it into the model and make PREDICTIONS.
• Limitation It still isnt the actual eventits
  a prediction and predictions can be wrong.

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Mathematical Model
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• 3rd Type Conceptual-qualitative models that help
  to diagram important interrelationships among
  processes and systems that we study.
• Limitation Againnot the real thingbut helps us
  understand the real thing.

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Conceptual Model