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TaK – Natural Sciences But Bob … in a quantum world - how can we be sure? Oh Alice… you’re the one for me!
TaK – Natural Sciences What are the Natural Sciences? What differentiates them from other Areas of Knowledge?
TaK – Natural Sciences What methodologies are used in the natural sciences?
TaK – Natural Sciences The Black Box A structure for which your description constitutes the only available truth In groups: What can we know about the internal structure of the box?
TaK – Natural Sciences The Black Box What we know can be different from what actually is
TaK – Natural Sciences All national education systems take the view that it is important to study science. Why?
TaK – Natural Sciences Eratosthenes
TaK – Natural Sciences Nicolaus Copernicus 1473 - 1543
TaK – Natural Sciences Ptolemy 90 – c.168 AD Copernicus
TaK – Natural Sciences Galileo Galilei 1564-1642 “…perhaps more than any other single person, was Responsible for the birth of modern science” Stephen Hawking
TaK – Natural Sciences • Key to the discoveries and developments of science have been: • Proper standards of measurement • Paper & printing • A common language of scholarship • Developments in instrumentation
TaK – Natural Sciences With telescopes and microscopes, enquirers (scientists) have made rapid progress in putting questions to nature, and in formulating answers
TaK – Natural Sciences “Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house” Henri Poincare
TaK – Natural Sciences “We found that the theory did not fit the facts – and we were delighted, because this is how science advances” O.R. Frisch
TaK – Natural Sciences The facts are coming! The facts are coming!
TaK – Natural Sciences Can we talk about ‘scientific truths*’ or should we talk about ‘scientific beliefs*’? *a verified or indisputable fact, proposition, principle *confidence in the truth or existence of something not immediately susceptible to rigorous proof
TaK – Natural Sciences “The progress of science is strewn, like an ancient desert trail, with the bleached skeletons of discarded theories which once seemed to possess eternal life” Arthur Koestler
TaK – Natural Sciences Can you think of examples of things that were believed to be true by 19th century scientists, but which we now know to be false?
TaK – Natural Sciences Who is a Scientist?
TaK – Natural Sciences • Who is a Scientist? • By temperament … • some scientists are collectors • some are classifiers • some are compulsive tidiers • some are detectives • some are explorers • some are artists • some are poet-scientists • some are philosopher scientists • … and more
TaK – Natural Sciences • Who is a Scientist? • In the broadest sense, we all can be… • ‘Science’ – • from the Latin ‘scientia’, meaning Knowledge ‘Science’ – an enterprise that builds and organises knowledge in the form of testable explanations and predictions about the natural world
TaK – Natural Sciences “Science is a way of thinking more than it is a body of knowledge” Carl Sagan
TaK – Natural Sciences • Searching for, • and finding, ‘Patterns’: • All bodies fall to earth • All plants… • All metals… • All liquids… • All ecosystems… • All chromosomes…
TaK – Natural Sciences The scientific method Put in order: Test with experiments Ask questions Think! Try again Draw conclusion Report results Background research Observation Construct hypothesis Analyze results
TaK – Natural Sciences Observation Ask question Background research Analyze results Test with experiment Construct hypothesis Hypothesis is False or partially True Think! Try again Draw conclusion Hypothesis is True Report results
TaK – Natural Sciences • ….. from Results you may be able to • develop a Law* which can then lead to a Theory*. • *A scientific Law is a distillation of the results of repeated observation. It does not offer an explanation of phenomena. • *A Theory explains a wide range of phenomena on the basis of a small number of key ideas. A model of reality.
TaK – Natural Sciences The scientific method • Problems with Observation: • Relevance • Selectivity • Expectations • Expert seeing • Observer effect
TaK – Natural Sciences The scientific method • Problems with testing Hypotheses: • Confirmation bias • Background assumptions
TaK – Natural Sciences The scientific method Problems with testing Hypotheses: What makes a hypothesis a good hypothesis?
TaK – Natural Sciences “We’ve discovered a massive dust and gas cloud which is either the beginning of a new star, or just an awful lot of dust and gas.”
TaK – Natural Sciences • Problems with Induction: • Reasoning from the observed, to the unobserved • How many observations should be made before we jump to a generalisation?
TaK – Natural Sciences According to Karl Popper, science should be based on the method of conjecture and refutations, and scientists should try to falsify hypotheses rather than verify them
TaK – Natural Sciences • Truth tests: • Correspondence • Statements scientists make must correspond to what can be observed in the world • Coherence • Observations and measurements should be consistent with each other and the explanations they give about phenomena should also be consistent with each other • Pragmatic • We accept certain assumptions without empirical proof – because they happen to work. For example, we assume that nature is regular and understandable; we assume that the laws of physics are applicable all across the physical universe.
TaK – Natural Sciences Scientific Progress…. or New explanations replace old through falsifying? New explanations coexist with old? Which? Why?
TaK – Natural Sciences Smooth progress Knowledge Time
TaK – Natural Sciences Other models of progress: Knowledge Knowledge Time Time Knowledge Knowledge Time Time
TaK – Natural Sciences • Paradigm* Shift • Thomas Kuhn: • A scientific revolution happens when scientists become unhappy with the prevailing paradigm. If their ideas triumph, the new paradigm will replace the old…. * Thought pattern shared by a community
TaK – Natural Sciences Revolution Normal Science Knowledge Revolution Normal Science Time
TaK – Natural Sciences Language What role do metaphors play in science? Emotion What does biology tell us about emotion? Perception How far do expectations influence observations? Ethics Are scientists morally responsible for how their discoveries are used? Religion How similar is faith in science to religious faith? Natural Sciences Arts What role does imagination play in the sciences? Human Sciences How do the human sciences differ from the natural sciences? History Should scientists know about the history of their subjects?
TaK – Natural Sciences • ToK Prescribed Titles 2010 • “What separates science from all other human activities is its belief in the provisional nature of all conclusions” (Michael Shermer, www.edge.org). • Critically evaluate this way of distinguishing the sciences from other areas of knowledge. • Keywords? • Knowledge Issues?
TaK – Natural Sciences • Some Key Points: • The success of the natural sciences has led some people to see them as the most important form of knowledge • The traditional picture of the scientific method has science consisting of five key steps: observation, hypothesis, experiment, law, theory • Since scientific laws are based on a limited number of observations, we can never be sure they are true • According to Karl Popper, science should be based on the method of conjecture and refutations, and scientists should try to falsify hypotheses rather than verify them • (However, a hypothesis can no more be conclusively falsified than it can be conclusively verified) • Although scientific beliefs change over time, it could be argued that each new theory is closer to the truth than the previous one
TaK – Natural Sciences Knowledge Creation Diagram Within context of the natural world Natural world influences what is studied, and how it is studied and the creation of knowledge has an effect on the natural world Works of Knowledge (math proof, research paper, novel etc) Knowledge Creator(s) Knowledge Community (peers, critics, general public) Within social context Societies influence how knowledge is created and judged and knowledge affects societies and cultures
TaK – Natural Sciences “You are completely free to carry out whatever research you want, so long as you come to these conclusions”