Download Variation - UWE Blackboard

Practice & Communication of Science
What is Science?
What is Science About?
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Formally speaking…
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“the intellectual and practical activity encompassing
the systematic study of the structure and behaviour
of the physical and natural world through
observation and experiment” (Google definition)
Somewhat less formally…
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intellectual and practical – thinking and doing
systematic study – organised, thorough
structure and behaviour – what things are and do
physical and natural – non-living and living
observation and experiment – passive vs active
What is Science About?
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Most informally…
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“Accounting for variation”
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Why accounting?
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We are aiming to explain rather than describe
Why variation?
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my personal definition
We are surrounded by variation in…
 structures (entities, things)
 and their behaviour (changes in relation to each
other)
Variation in structure/behaviour underpins
everything
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Accounting for that is what science is about
Variation in Structure/Behaviour
is Everything
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Take vision…
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Relies on light propagation and objects in world
behaving differently by virtue of their structures
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Relies on chemical/electrical variation/behaviour
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“If objects were entirely transparent they would be
invisible” (R Tallis – The Kingdom of Infinite Space)
Light’s interaction with visual pigments
Na+ and K+ diffusion, ATP hydrolysis
Myelin insulating properties, protein ion channel
Above all, vision characterised by change
Things do not ‘happen’ unless things ‘change’!
The Aim of Science
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To explain the largest number of natural
phenomena with the fewest principles
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That is the ‘direction’ that science moves in
But it often seem to get more complicated!
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As our knowledge base increases
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Global scientific output doubles every 9 years (Nature
newsblog, May 07 2014)
Accumulation of detail precedes ‘collapse’ into
explanation
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Petabytes of LHC data  Higgs Boson
Darwin’s years of observation  Natural Selection
The Aim of Science
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To predict the future, and thereby change it
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Is beef safe to eat?
Will this drug cure this disease?
What does it mean if I have this set of genes?
What will happen if CO2 continues to rise?
Science recognises itself as a ‘work in progress’
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it is driven by ignorance
The Role of Ignorance in Science
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Ignorance plays a critical role in science
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“The fuel on which science runs is ignorance. Science is like
a hungry furnace that must be fed logs from the forests of
ignorance that surround us. In the process, the clearing that
we call knowledge expands, but the more it expands, the
longer its perimeter and the more ignorance comes into
view. . . . A true scientist is bored by knowledge; it is the
assault on ignorance that motivates him - the mysteries that
previous discoveries have revealed. The forest is more
interesting than the clearing.”
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Matt Ridley. Genome: the autobiography of a species
in 23 chapters, p 271 (1999)
“Science is the belief in the ignorance of experts”
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R Feynman, American Scientist v87, p462 (1999)
The Provisional Nature of Science
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What science can know is incomplete in both
theory and practice
Theoretical limits of knowledge…
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Plato’s cave
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Scientific Revolution – circa 17th century on
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Our view of reality as but shadows on a cave wall
Success suggested determinable universe
Kant’s Critique of Pure Reason (1781)
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‘thing-in-itself’ unknowable; only things as they
appear (phenomena)
The Provisional Nature of Science
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Theoretical limits of knowledge…
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20th Century shocks
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Quantum theory
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Gödel's Incompleteness Theorems
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Indeterminacy, randomness a feature of reality
All complex logical systems are incomplete
“…doomed also, as a result, is the ideal of science to devise a set of axioms from which all phenomena
of the external world can be deduced” CB Boyer, A
History of Mathematics (1991)
Seems irrelevant to our day-to-day lives, but…
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How can we be 100% sure that…
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things will work tomorrow the way they did today?
things will work over there as they do here?
The Provisional Nature of Science
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Practical limits of knowledge…
Observations are incomplete and error-prone
So, all scientific interpretations are fallible
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This is a strength of science! It discourages dogma
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“Science alone of all the subjects contains within
itself the lesson of the danger of belief in the
infallibility of the greatest teachers in the preceding
generation.”
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R Feynman, American Scientist v87, p462 (1999)
Major shift occurred around 1600
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Scholasticism  Modern Science
Studying existing knowledge  accumulation of
evidence (ie beginnings of the Scientific Method)
The Provisional Nature of Science
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Scientific interpretations are falsifiable
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Science is the current ‘best guess’, open to being
disproved; it is falsifiable
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“…we shall have to get accustomed to the idea that
we must not look upon science as a ‘body of
knowledge’, but rather as a system of hypotheses, or
as a system of guesses or anticipations that in
principle cannot be justified, but with which we work
as long as they stand up to tests, and of which we
are never justified in saying we know they are ‘true’”
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K Popper (1902-94), The Logic of Scientific Discovery
Assertions that are not falsifiable are not scientific
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Bertrand Russel’s cosmic teapot
burden of proof on the proposer, not us!
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Bottom Line
Scientific thinking can be counter-intuitive
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incomplete, limited, provisional, fallible, ignorance
involves lots of rigorous data-handling
but “science a tribute to what we can know
although we are fallible” J Bronowski, AoM, 1976
And give me Science over Superstition any day!