Just How Does Science Work

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Just How Does Science Work?

• The History and Philosophy of science for KS4?

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What is science?

• Does following the scientific method make
  something science?
• Does doing experiments make science science?
• Is science a way of understanding, explaining
  and predicting the world in which we live?

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Foundations of Science

• Thales of Miletus 624 BC - 546 BC (circa)
• Before Thales, nature was due to the action of
  the Gods (e.g. thunder, earthquakes etc.)
• Thales attempted to find naturalistic
  explanations of the world, without reference to
  the supernatural.

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Aristotle 384 322 BC/BCE

• One of the most prolific natural philosophers,
  made countless observations of nature, especially
  the habits and attributes of plants and animals.
  Aristotle focused on categorizing. He also made
  many observations on the large-scale workings of
  the universe, which led to the development of a
  comprehensive theory of physics.

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Sir Francis Bacon (1561-1626) Inductive Science

• Revolves on the collection of unbiased
  observations, or inductive reasoning
• Contrasts with Aristotelian deductive reasoning
  or cause and effect
• Experimental gathering data and developing
  hypotheses and rules.

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Sir Karl Popper (1902 1994) Deductive
Falsification

• Believed in a creative force in scientific
  thinking
• Everyone will have a bias
• Stated that science advances by deductive
  falsification through a process of conjectures
  and refutations
• If a theory can be shown to be falsifiable then
  it is scientific
• Experiment and observations test theories they do
  not necessarily produce theories.

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Thomas Khun (1922 1996) Scientific Revolutions

• Science adopts different paradigms, or models
  of scientific explanation
• In time these models are replaced by other models
  which are better suited to the evidence
• The new model does not completely disregard the
  previous model and the two can co-exist
• e.g. Newtonian and Einsteinian physics.

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Inductive reasoning

• Observations
• The ice is cold.
• A football moves when kicked
• These observations can be used to infer that
• All ice is cold.
• There is no ice in the Sun.
• For every action, there is an equal and opposite
  reaction.
• Anything kicked moves.

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Inference

• Inference is the act or process of deriving a
  conclusion based solely on what one already knows
  
• The conclusion inferred from multiple
  observations is made by the process of inductive
  reasoning. The conclusion may be correct or
  incorrect, and may be tested by additional
  observations

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Strong induction

• All Observed sheep are white
• Therefore
• All sheep are white

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Weak induction

• GM crops may cause health concerns
• Therefore
• All GM crops are bad
• One type of superbug kills
• Therefore
• All superbugs kill

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The deductive method

• Starts with a few true statements (axioms) with
  the goal of proving many true statements
  (theorems) that logically follow from them

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Deductive Reasoning

• Deductive conclusions can be valid or invalid

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Valid Deductive reasoning

• All men are mortal
• Socrates is a man
• Therefore Socrates is mortal
• The picture is above the desk
• The desk is above the floor
• Therefore the picture is above the floor
• All birds have wings
• A thrush is a bird
• Therefore a thrush has wings

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Invalid Deductive Reasoning

• A bat has wings
• A bird has wings
• Therefore a bat is a bird
• Fundamentalist Muslim men have beards
• Most Muslim men have beards
• Therefore most Muslim men are fundamentalists

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What does Science Use?

• The inductive method
• The inductive method starts with many
  observations of nature, with the goal of finding
  a few, powerful statements about how nature works
  (laws and theories).
• In the scientific method, observation of nature
  is the authority
• If an idea conflicts with what happens in nature,
  the idea must be changed or abandoned.

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Who uses the deductive method?

• In the deductive method, logic is the authority.
  If a statement follows logically from the axioms
  of the system, it must be true
• For theorems and proofs of theorems see
  mathematics

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Definitions

• Fact
• An objective and verifiable observation
• Hypothesis
• A suggested explanation of a phenomenon
• Theory
• a logically self-consistent model or framework
  for describing the behaviour of a related set of
  natural phenomena
• Law
• A scientific generalization based on empirical
  observations also based on the confirmation of
  hypotheses through repeated scientific
  experiments which have become accepted
  universally within the scientific community
• Scientific laws are observations that have never
  had repeatable contradictions

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What ideas do Trainee teachers have of The
Scientific Method?

• Sample 25 trainees (all Sussex)
• F16 M9 (18lt30 4lt40 3gt40)
• Definitions
• 56 equate fact with truth and proven
• 48 cast a theory as unproven ideas
• 40 defined a law as a rule not to be broken, 20
  as a theory that science supports

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Preliminary analysis of a sample of specifications

• Edexcel 360 (section on HSW)
• Law 6 references
• 2 legal issues 3 Avogadros law 1 physics
• Theory 14 references
• Including consider the contemporary scientific
  theory of designer babies
• Hypothesis 0 references

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• Edexcel 360 (theory references)
• Evolution 3
• Designer babies 1
• Periodic table 1
• Global warming 1
• Big bang 1
• Oscillating, steady state, collision theory 3
  (gloss)
• Theory of relativity 4 (include 1 in glossary)

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• OCR Gateway (no section on HSW)
• Law 0 references in a scientific context
• Theory 11 references
• 4 evolution/natural selection
• 2 plate tectonics
• 2 big bang
• 1 kinetic theory
• 1 atmospheric evolution
• Hypothesis 1 reference (dinosaur extinction)

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• AQA (section on HSW)
• Law 0 references
• Theory 6 references
• 4 evolution/natural selection
• 1 crustal movement
• 1 big bang