Observationally constrained model building Byron Jennings TRIUMF Global warming and C02 levels Alternate medicine Vaccination and autism Cell phones and cancer Size of salmon runs The elephant on the room ID: 685160
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Science Simplified
What is Science?
Observationally constrained model building!
Byron Jennings | TRIUMFSlide2
Global warming and C02 levelsAlternate medicine
Vaccination and autismCell phones and cancerSize of salmon runs
The elephant on the roomEvolution and creationismWhy Science Matters
March 12, 2013
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Disappointing talks on selling science Believing Bullshit: How Not to Get Sucked into an Intellectual Black Hole, Stephen Law
Are we just selling another religion (belief system)?Rick Warren (Saddleback): The Purpose Driven Church
To sell science we should know what it is. Science is not philosophyCompeting paradigms for the nature of knowledge
Selling science
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Most scientists have a good operational understanding of scienceLack a formal understanding
Has changed over timeCan lead to misunderstandings and wasted effort
Doing Science
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Learned how the universe worksChanged our conception of man’s role in the universe
Big historyBig bang, evolution, etc
Laid the foundation for technologyIncreased life expectancy
Mankind's Greatest Achievement
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Protagoras (490BCE – 420 BCE): SophistryPlato (424 BCE – 348): Shadows in the cave
Antisthenes (445 BCE – 365 BCE): CynicismDescartes ( 1596 – 1650): Skepticism Hume (1711 – 1776): Induction does not exist
Kierkegaard (1813 – 1855), Nietzsche (1844 – 1900): Post-modernismFeyereband (1924 – 1994) Against Method: Outline of an Anarchistic Theory of Knowledge
The Opponents – 1) Skepticism
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I think therefore I am.Criticized by Nietzsche and Bertrand Russell
This is sentence is the sum total of all 100% certain knowledge.And I am not even sure about that. Sure and certain knowledge:
A set of measure zero (probably not the null set)Sure and Certain Knowledge
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Sophistry: Argument rather that knowledgeReplace knowledge with rhetoric.
Idealism: It is all in the mind.Plato: Ideals (ideas, forms)
Descartes (1596 – 1650) : What I perceive clearly and distinctly as being true is true. Berkeley (1685 – 1753): To be is to be perceived
Kant (1724 – 1804): Synthetic a priori knowledgeScience: Practical rather than certain.We may be studying the reflections on a wall (as Plato suggested) but at least we do a good job of it.
Popper: Falsification not verificationProgress not certaintyResponses to Skepticism
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Disconnect from realityCreationism
Global warmingDistance from the dataRepublican surprise they lost the presidential election
The Opponents – 2) The Religious Right
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The aide said that guys like me were "in what we call the reality-based community," which he defined as people who
"
believe that solutions emerge from your judicious study
of
discernible reality." ... "That's not the way the world really
works
anymore," he continued. "We're an empire now, and
when
we act, we create our own reality. And while
you're studying
that reality—judiciously, as you will—we'll act again,
creating other
new realities, which you can study too, and that's how things will sort out. We're history's actors…and you, all of you, will be left to just study what we do.Slide10
Science – the reality based community has:
Changed the world’s intellectual landscapeLaid the foundation for technological advancesis:
Necessary to understand the issues confronting the world today.But what is it?
Science
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The Scientific Method
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The essentialsObservation
Model buildingSimplicityPredictions
Testing against additional observationsNon-essentialsTRUTH™NaturalismExplanations
Peer review
The EssentialsMarch 12, 2013Presentation Title
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Observations
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Science is built up of facts, as a house is built of stones; but an accumulation of facts is no more a science than a heap of stones is a house.
Henri PoincareSlide14
ModelsParadigm
Framework that ties the observations together.Illusion of understandingCreative activity
SimplicityOmphalos hypothesisAnarchy
No algorithm that does from observations to the models. Models & Paradigms
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Provides the framework for a given fieldwhat is to be observed and scrutinized
the kind of questions that are supposed to be asked and probed for answers in relation to this subject
how these questions are to be structuredhow the results of scientific investigations should be interpretedScience
and engineering are defined by a common paradigm on what constitutes knowledge.
ParadigmMarch 12, 2013
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Philosophy and science are competing
paradigmsThomas Kuhn: Aristotle versus NewtonBertrand Russell:
“Change” in philosophy when science discoveredScientists know very little about the what philosophers of science are doing. And the ones that do:Carl Sagan
: Attack on PlatoRichard Feynman: Philosophy of science is about as useful to scientists as ornithology is to
birds.Lawrence Krauss: It has no impact on physics what so ever,C.P. Snow: Two Cultures (science and humanities) 1959 Rede Lecture
Paradigm ExampleMarch 12, 2013
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Philosophy (in the western tradition)Based on
rational arguments and word definitionsPure thought not observationScience
Based on observationConstruct models based on the observation of past observations and test based on predictions for future observations.A rational argument is one that can be used to predict future observations.
Philosophers will never understand science and vise versa
Philosophy and ScienceMarch 12, 2013
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The ultimate test of any model.The problem of evil
OmphalosDemarcation criteriaThe ability to make
testable predictions about future observationsPredictions
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William of Ockham (1285 – 1349)Occam’s razor:
The razor asserts that one should proceed to simpler theories until simplicity can be traded for greater explanatory power
.Simplicity absolutely necessary.An arbitrary number of curves can be drawn through any set of points. Simplicity frequently trumps accuracy but in the end it fails.
Simplicity
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Simplicity
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is a measure of the minimum computational
resources needed to specify the data object.is not a computable function. 690927210797509302955321165344987202755960236480665499119881834797753566369807
If simplicity in the sense of Kolmogorov complexity is needed to define a scientific model, you cannot get from experimental data to a scientific model algorithmically.
Kolmogorov complexity
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Deep BreathSlide22
To Err is human, to control error science.Error control is a scientists day job.
Very few toolsCare in doing the experimentBlind analysis
Double bind medical testsUselessness of testimonials.Independent checkingPeer review
OpennessIncompatible with intellectual property.Independent repetition
Error controlMarch 12, 2013
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All ravens are black.All non-black objects are not ravens.
Logically equivalentBayesian resolutionMore non-black objects than ravens
Model comparisonAll ravens are greenFalsificationNot all ravens are black.
The Raven Paradox
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Popper
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For science does not develop by a gradual encyclopaedic accumulation of essential information, (as Aristotle thought) but by a much more revolutionary method; it progresses by bold ideas, by the advancement of new and very strange theories (such
as the theory that the earth is not flat, or that ’metrical space’ is not flat), andby the overthrow of the old ones.Slide25
Popper
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We have learnt in the past, from many disappointments, that we must not expect finality. And we have learnt not to be disappointed any longer if our scientific theories are overthrown; for we can, in most cases, determine with great confidence which of any
two theories is the better one. We can therefore know that we are making progress; and it is this knowledge that to most of us atones for the loss of the illusion of finality and certainty.Slide26
But, as many skeptics pointed out, rival theories are always indefinitely many and therefore the proving power of experiment vanishes. One cannot learn from experience about the truth of any scientific theory, only at best about it falsehood:
confirming instances have no epistemic value whatsoever (emphasis in the original
). Imre Lakatos (1922 – 1974),
Falsification
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Is a modelLimited range of validity (lacks gravity)
Describes a wide range of phenomena.QED, QCD, electroweak, Hadron and nuclear structure?
Simpler than its competitorsSuper symmetry, technicolor, little Higgs, grand unificationQuestion:
Not: Is it correct?But: Where does it break down?
The Standard ModelMarch 12, 2013
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The Standard Model
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The OptimistThe optimist fell ten stories And at each passing window bar
He shouted to his friends— 'All right so far.‘UnknownSlide29
Empirical
Testable predictionsModel buildingCreative not algorithmic Bottom up
Solve one problem at a timeSimplicitySolves non-uniqueness problemAccumulative
Build on past successTentativeNot sure and certain but progressive
Science: In conclusionMarch 12, 2013
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Primary Reference
Henri Poincaré (1854 – 1912)
Science and Hypothesis, 1905Chapters – IX, XSecondary ReferencesThomas Kuhn (1922 –1996)
Structure of Scientific Revolutions (1962)Paradigms
Karl Popper (1902 –1994)The Logic of Scientific Discovery (1943)Progress not certainty, falsificationNicolas T. Wright, Bishop of Durham (Anglican)The New Testament and the People of God, 1992Model building and testing (M. Polanyi. T.F. Torrance)
ReferencesMarch 12, 2013
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Common View:Flowering of intellectual activity in the ancient world (notably Socrates, Plato, Aristotle) was suppressed by the Christian church until Galileo broke free.
Alternate View: Greek philosophy and math were dead ends
Its medieval revival, scholasticism, also a dead endGalileo’s opponents where as much the philosophers as the theologiansScience owes
as much to alchemy as to Aristotle.
History of ScienceMarch 12, 2013
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Observations
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Carlyle has written somewhere something after this fashion. " Nothing but facts are of importance. John Lackland passed
by here. Here is something that is admirable. Here is a reality for which I would give all the theories in the world." Carlyle was a compatriot of Bacon, and, like him, he wished to proclaim his worship of
the God of Things as
they
are.
But
Bacon would not have said that. That is the
language
of the historian. The physicist would most likely
have
said: "John
Lackland
passed by here. It is all the same
to
me, for he will not pass this way again."Slide34
History
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Abu Mūsā Jābir
ibn Hayyān (721 – 815): Alchemist and the first chemist.
Frederick II, Holy Roman Emperor (1194 – 1250): ExperimenterRoger Bacon (1214 – 1294): Inventor of the scientific method?Dr. Johann Georg Faust (1480 – 1540): Sold his soul to the devil for knowledge.
Under the radar
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A. N. Whitehead
: The safest general characterization of the European philosophical tradition is that it consists of a series of footnotes to Plato.Carl
Sagan: Plato, Aristotle and the Pythagoreans were suppressors of knowledge, advocates of slavery and of epistemic secrecy. Plato’s followers succeeded in extinguishing the light of science and experiment that had been kindled by Democritus and the other Ionians. Plato’s unease with the world as revealed by our senses was to dominate and stifle Western philosophy
.
PlatoMarch 12, 2013
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