Exploring Life and Science

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Chapter 1

• Exploring Life and Science

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What do we know about science?
1.3 Science is a process

• Science is a way of knowing about the natural
  world
• Science and scientists should be objective
• Scientific conclusions may change or be modified
  as our understanding and technology increase
• Science is studied using the scientific method

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The steps of the scientific method
1.3 Science is a process
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The scientific method in action
1.3 Science is a process

• Observations many patients had a particular
  bacterium near their ulcers
• Hypothesis Helicobacter pylori is the cause of
  gastritis and ulcers.
• Experiment/observations
• 1st H. pylori was isolated and grown from
  ulcer patients
• 2nd humans swallowing a H. pylori solution
  resulted in inflammation in their stomachs
• Conclusion H. pylori was the cause of most
  ulcers and can be cured by antibiotics

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A controlled study
1.3 Science is a process

• Variables
• Experimental variable is the variable that is
  purposely changed or manipulated
• All other variables need to remain constant
• Groups
• Test group is a group of subjects that are
  exposed to the experimental variable
• Control group is a group for comparison that is
  not exposed to the experimental variable

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A controlled study in action
1.3 Science is a process
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Reading about scientific information
1.3 Science is a process

• Scientific journals are considered the best
  source of information but can be difficult for
  the lay person to understand
• Often the lay person reads secondary sources and
  must be wary of information taken out of context
• Be careful of information on the Internet by
  using reliable sources such as URLs with .edu,
  .gov and .org

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What should you look for when you read about
science?
1.4 Making sense of a scientific study

• Beware of anecdotal data
• Understand methodology and results
• Does the data justify the conclusions inferred by
  the scientists?
• Be able to read a graph
• Have some understanding of statistics

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Scientific Theory

• Is not an opinion or idea
• Is free of value judgments and beliefs (objective
  in nature)
• Is as close to fact as you can get in science
• No absolute truths in science
• Is different from a lay persons theory
• Is the best explanation for a concept we have
  with our technology and knowledge

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Scientific Theory

• Is based on hypotheses that have been repeatedly
  tested and have not been disproved
• May be modified but not thrown out
• Theories are not proven false, only hypotheses
  are
• We do not know all aspects of theory
• New discoveries lead to new questions
• Has predictability
• Is accepted by the scientific community
• Is generally accepted as valid due to having
  survived repeated testing

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http//en.wikipedia.org/wiki/Theory

• The word theory has a number of distinct meanings
  in different fields of knowledge, depending on
  their methodologies and the context of discussion.

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http//en.wikipedia.org/wiki/Theory

• In common usage, people often use the word theory
  to signify a conjecture, an opinion, or a
  speculation.
• In this usage, a theory is not necessarily based
  on facts in other words, it is not required to
  be consistent with true descriptions of reality.
• True descriptions of reality are more
  reflectively understood as statements which would
  be true independently of what people think about
  them.
• In this usage, the word is synonymous with
  hypothesis.

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• In science, a theory is a mathematical or logical
  explanation, or a testable model of the manner of
  interaction of a set of natural phenomena,
  capable of predicting future occurrences or
  observations of the same kind, and capable of
  being tested through experiment or otherwise
  falsified through empirical observation.
• It follows from this that for scientists "theory"
  and "fact" do not necessarily stand in
  opposition.
• For example, it is a fact that an apple dropped
  on earth has been observed to fall towards the
  center of the planet, and the theories commonly
  used to describe and explain this behaviour are
  Newton's theory of universal gravitation (see
  also gravitation), and general relativity.

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• In scientific usage, a theory does not mean an
  unsubstantiated guess or hunch, as it can in
  everyday speech. A theory is a logically
  self-consistent model or framework for describing
  the behavior of a related set of natural or
  social phenomena.
• It originates from or is supported by
  experimental evidence
• In this sense, a theory is a systematic and
  formalized expression of all previous
  observations which is predictive, logical and
  testable.
• In principle, scientific theories are always
  tentative, and subject to corrections or
  inclusion in a yet wider theory. Commonly, a
  large number of more specific hypotheses may be
  logically bound together by just one or two
  theories.
• As a general rule for use of the term, theories
  tend to deal with much broader sets of universals
  than do hypotheses, which ordinarily deal with
  much more specific sets of phenomena or specific
  applications of a theory

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Theory

• In principle, scientific theories are always
  tentative, and subject to corrections or
  inclusion in a yet wider theory.
• Commonly, a large number of more specific
  hypotheses may be logically bound together by
  just one or two theories.
• As a general rule for use of the term, theories
  tend to deal with much broader sets of universals
  than do hypotheses, which ordinarily deal with
  much more specific sets of phenomena or specific
  applications of a theory