Science News

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Science News
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Science (?) News
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Demarcation

• We scientists believe that the world is
  knowable, that there are simple rules governing
  the behavior of matter and evolution of the
  universe and that the collection of these
  truths is what we call physical science. Any
  intelligent alien anywhere would have come upon
  the same logical system as we have to explain the
  structure of protons and the nature of
  supernovae.
• This statement I cannot prove. This statement I
  cannot justify. This is my faith.
• Sheldon Glashow, Nobel Laureate Physics, Harvard

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The commitments of Glashows credo

• Epistemological the world is knowable and the
  physical sciences have a lot of this knowledge
• Simplicity there are simple rules governing the
  behavior of matter and evolution of the universe
• Realism and, thus, intersubjectivity any
  intelligent alien anywhere would have come upon
  the same logical system as we have to explain the
  structure of protons and the nature of
  supernovae.
• Fallibilism This statement I cannot prove. This
  statement I cannot justify. This is my faith.

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Commitments displayed in The Elegant Universe

• Epistemological
• If a theory (such as String Theory) isnt
  testable, then no one should believe/accept it
  whatever its other merits.
• If String Theory isnt testable (e.g., strings by
  hypothesis can not and will not be observed), one
  needs to worry if it is science or, rather,
  philosophy that is, metaphysics in Ayers
  sense.
• Quasi (at least) Metaphysical
• There is a theory of everything,, even if we
  dont yet know what it is, and it is simple and
  elegant.

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Commitments displayed in The Elegant Universe

• Aesthetic/theoretical/epistemological and/or
  metaphysical
• Simplicity
• Elegance
• Unification
• Unifying Quantum Theory and Relativity
• The physics of the very small and the big
  (including the very big)
• Indeterminacy (at the quantum level) and
  Determinacy at the macroscopic level

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Demarcation

• A.J. Ayer
• Logical Positivism (Logical Empiricism)
• Distinguishing science from non-science
  (including metaphysics) and from pseudo-science
• At its core logic and empiricism
• Arguing for the positive difference science can
  make in the world.
• Seeking to expose what makes non- or
  pseudo-science just that.

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Demarcation

• The target (A particular form of) Metaphysics
• Any effort to discover a transcendent reality
  or any claim to have discovered aspects of such a
  realty
• Transcendent reality A reality that transcends
  (goes beyond, hides behind) the world of science
  and common sense.
• Verifiability Scientific claims and theories,
  unlike non-scientific claims and theories (e.g.,
  metaphysical claims) can be verified (shown to be
  true) through observation.
• A sentence is factually significant (meaningful)
  if, and only if, there are observations that
  would lead one to accept that sentence as true
  or reject it as being false.

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Demarcation

• A sentence is factually significant (meaningful)
  if, and only if, there are observations that
  would lead one to accept that sentence as true
  or reject it as being false.
• If, alternatively, the truth or falsity of a
  sentence is consistent with any and all future
  observations, it is a pseudo sentence or claim.
• What of kinds of sentence (say, ethical, or a
  line of poetry or of a novel) that dont meet
  this criterion but also dont claim to be
  scientific. Are they meaningless?

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Demarcation

• What about sentences (say, ethical such as
  Murder is wrong, or a line of poetry or of a
  novel) that dont meet this criterion but also
  dont claim to be scientific. Are they
  meaningless?
• Literally, yes. Though they may carry emotional
  meaning for an individual, they lack factual
  significance.
• They do not constitute a claim about a matter of
  fact.

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Demarcation

• Fine-tuning the criterion and argument for it
• The distinction between practical verifiability
  and verifiability in principle
• Some sentences are practically verifiable we can
  undertake the observations that demonstrate their
  truth.
• Some sentences cannot be verified practically (or
  we do not feel the need to attempt to verify
  them) but are verifiable in principle Simply
  because we lack the physical capacity or
  technical means to do so (that red school
  house). Yet we do know what observations of
  matters of fact would verify them.

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Demarcation

• Fine-tuning the criterion and argument for it
• Understanding to verify as to establish or
  discover the truth of a sentence, we need to
  decide between strong or conclusive
  verifiability, and a weaker sense.
• Conclusive verifiability would call for too much,
  ruling out the laws and generalizations so
  important to science that yield an infinite
  number of observational predictions as anything
  more than nonsense, albeit important
  nonsense.

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Demarcation

• But as such statements are important features of
  science (if not basic to science), ruling them
  out as nonsense is wrongheaded.
• Better to adopt a more reasonable but still clear
  criterion involving verifiability
• Namely, a sentence or claim of any sort is
  genuine only if it is verifiable, and it is
  verifiable if it possible for observations/experie
  nce to render it probable.

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And now, as Monty Python would say, for something
completely different (?)

• (Sir) Karl Popper
• Science the autumn of 1919, wrestling with the
  question Is there a criterion for the scientific
  character or status of a theory?
• Distinct from the question When is a theory true
  or acceptable?
• Alternatively put, what distinguishes a genuinely
  empirical method and a non- or pseudo empirical
  method?

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Poppers Falsifiability

• Comparing 4 then popular and much discussed
  theories Relativity, Marxism, Freudianism, and
  Adlerian Psychology
• Although each of the latter three might contain
  important truths or insights, and although they
  are said to enjoy extensive confirmations
  (supporting observations and experiences), they
  turn out not to be scientific.
• Although it was unclear at the time whether
  Einsteins theory was true, it turns out to be
  scientific.

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Poppers Falsifiability

• The criterion used to make these judgments and to
  be generalized Falsifiability
• Every genuinely scientific theory is a
  prohibition. It forbids certain things to happen.
• A theory that is not falsifiable (refutable) by
  any conceivable event is not scientific.
• Relativity does prohibit or forbid certain things
  to happen. Moreover its predictions are bold
  and risky. And 1919 brought about the first
  important confirmation of it.

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Poppers Falsifiability

• The criterion used to make these judgments and to
  be generalized Falsifiability
• So what is wrong with the other three?
• After all, Popper concedes they enjoy numerous
  confirmations (or verifications in Ayers terms).
• But Popper also maintains that numerous
  confirmations should not count unless they are
  bold and risky.
• For Popper, none of the three is falsifiable.
• But what does this mean?

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Poppers Falsifiability

• The criterion used to make these judgments and to
  be generalized Falsifiability
• For Popper, none of the three is falsifiable.
• But what does this mean?
• Two (exclusive?) senses
• Each theory is compatible with any and all
  relevant observations, events, experiences, etc.
• Advocates of each theory see confirmations
  everywhere and explain away apparent
  counter-examples.

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Similarities and Differences

• Shared interest in demarcation criterion
• Emphasis on matters of fact, observations,
  experience
• Emphasis on evidential relations as logical.
• The difference
• Ayer emphasizing the importance of confirmation
  or verification
• Popper drawing on the fact that while a
  generalization can never be proven (conclusively
  verified), it can be falsified.