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History and Philosophy of Science and Technology
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Lecture 1- Introduction to History and Philosophy of Science History of Science -We are interested in the history of scientific theories and the changes in the mosaic of accepted theories. -The history of science shows that the mosaic of accepted theories changes through time. Scientific Mosaic -A set of theories accepted by the scientific community of the time. -The mosaic is always in the process of constant change. Scientific Change -Any change in the scientific mosaic. -Example: Over the years, there are several types of Theories of Free Fall: 1) General Relativity: The apple is in a state of inertial motion in a curved space. 2) Newtonian Physics: The apple is moving with acceleration being pulled by the Earth’s gravity. 3) Aristotelian Physics: The apple, a heavy body, is descending towards the centre of the universe. Philosophy of Science -Physical Theories: General Relativity, Newtonian Physics, Aristotelian Physics -Astronomical Theories: Contemporary Astronomy, Kepler’s Astronomy, Geocentric Astronomy -As physical theories and astronomical theories have changed, are there any theories immune to change or does everything in the mosaic change? -Is there absolute knowledge? -Is there scientific knowledge? Reading 1 -Worldview is a system of beliefs that are interconnected, intertwined, interrelated like a jigsaw puzzle. It starts with a core belief which then connects to many other peripheral. However, trying to replace one belief would mean that the whole worldview would have to change. -Aristotelian Worldview was a dominant system of beliefs that shared by a large segment of western culture after his death and largely based on his beliefs. -Aristotelian Worldview: The Earth is in the centre of the universe. -Newtonian Worldview: The Earth revolves on its axis, completing a revolution every 24 hours. Lecture 2- Analytic and Synthetic Propositions Can analytic propositions be absolutely certain? YES, because analytic propositions are either definitions or follow from definitions. Analytic Propositions 1) Deducible from definitions. 2) Cannot contradict the results of experiments or observations. 3) Necessarily hold in all possible worlds: the opposite is inconceivable. Example: Mathematics follows a pattern where some basic theorems follows immediately from definitions and subsequent theorems will follow with the combination of a definition and another theorem and so on. -All propositions of formal sciences (e.g. mathematics, logic) are analytic. -Once proven, a mathematical theorem remains in the mosaic forever. Can synthetic propositions be absolutely certain? NO, theories in empirical science cannot be absolutely certain. Synthetic Propositions 1) Not deducible from definitions. 2) Can contradict the results of experiments or observations. 3) Do not necessarily hold in all possible worlds: the opposite is conceivable. -Intuitive answer: It must be somehow based on experience – our observations and experiments . -Example: In theory, all swans are white because it is based on our experience that each individual swan is white. Or Gravity -This is a synthetic proposition as there is a possibility of a black swan. -Most propositions of empirical science are synthetic (e.g. physics, biology, sociology), because the opposite is conceivable. -Apparently, all synthetic propositions, such as laws of physics, chemistry, biology, psychology, sociology, or economics, must be somehow based on experience. This presents 3 major problems. 1) Problem of Induction No matter how many confirming instances are observed, inductive generalizations remain fallible. 2) Problem of Sensations There is no guarantee that senses convey the exact picture of things as they really are. 3) Problem of Theory-Ladenness The results of experiments and observations are shaped by our accepted theories. Fallibilism -Capable of making mistakes. -No synthetic proposition is infallible. Empirical knowledge cannot be absolutely certain. Reading 2 Representational theory of perception A general theory about perception involving all our senses. Our sense provide representations of things in the external world. There is no way for us to know if our senses are accurate or is there a way to knowing for sure what reality is like. Hume's Problem of Induction The assumption that nature is uniform and regular, and things might be different outside of our limited experience and history. We might see only white swans, and by induction conclude that all swans are white. The problem is that we just haven't yet seen a black swan. We assume nature is uniform - if it is a swan it must be white, or regular - why should there be exceptions? Hempel's Raven Paradox Illustrates a problem where inductive logic violates intuition. It reveals the problem of induction. Goodman's Gruesome Problem He accepted Hume's observation that inductive reasoning was based solely on human habit and regularities to which our day-to-day existence has accustomed us. Goodman argued, however, that Hume overlooked the fact that some regularities establish habits while some do not. How then can we differentiate between hypotheses that construe law-like statements from those that are contingent? Lecture 3- How Theories become accepted? Acceptance -A theory is accepted if it is taken as the best available description of its fragment of reality. -An accepted theory remains accepted unless replaced by other theories. -Two contradicting theories can be simultaneously used, pursued, but not accepted. Only one of the alternatives can be accepted at a time. -Accepted theories: Quantum physics, general relativity. Use -A theory is considered useful if it is taken as an empirically adequate tool for making calculations. - Old tools do not necessarily get replaced by new ones. -Two theories that contradict each other can be simultaneously used in practical applications. E.g. Classical Physics and General Relativity nowadays -The only requirement is that a new theory must be useful in one way or another. -Used theories: Classical physics, law of gravity. Pursuit -A theory is pursued if it is considered worthy of further development. -It is hard to tell from the outset which initial idea is worthy of further elaboration and which one is not. -We should not impose any limitations as to which ideas are worth developing. -Pursued theory: Superstring theory. Method -A set of rules for theory assessment. -In order to tell which theory is better, we need a method of appraisal to determine which theory is better in light of the available evidence. -Methods are not something external to the mosaic. -Now, we believe that there is no universal and unchanging method of science as methods do change. -In the most basic case, we prefer a theory which is the most accurate and precise fit to the available data. -Precision and Accuracy alone are often not enough for a theory to become accepted. Novel Predictions: Newtonian Theory -They are First Law, Second Law, Third Law and Law of Gravity. -The theory became accepted only after the confirmation of one of its novel predictions. Yet, despite its accuracy, the theory remained unaccepted for more than half a century. By postulating the existence of the universal force of gravity the theory provided very accurate predictions for a wide range of terrestrial and celestial phenomena. Accepted Ontology -The accepted views on the types of entities and interactions that populate the world. -In order to become accepted, the new theory must fit the known data with more precision and accuracy than the accepted theory and must also provide confirmed predictions of hitherto unobserved phenomena. -Example: In 1810, Corpuscular theory of Light was the accepted theory. And then, Fresnel came up with the wave theory of light which was only accepted in 1819 when Francois Arago gave the confirmation of its novel prediction. Scientific Methods Hypothetico-Deductive Method -A hypothesis is allowed to introduce unobservable entities provided it predicts something novel, hitherto unobserved, and some of these predictions are confirmed. Nowadays, new theories must satisfy this requirement in order to become accepted. -In order to become accepted, the new theory must fit the known data with more precision and accuracy than the accepted theory and must also provide confirmed predictions of hitherto unobserved phenomena. Aristotelian-Medieval Method -In contrast with the HD method, Aristotle’s method did not require any novel predictions or experimental confirmations. This requirement was so vague that many different theories could easily satisfy it: The theorem is grasped intuitively by an experienced person and deduced by axioms. -A proposition is acceptable if it grasps the nature of a thing through intuition schooled by experience, or it is deduced from the general intuitive propositions. Example: -Copernican theory of moving Earth was not accepted because it was not an intuitive truth. -Cartesian’s Theory was accepted not because it had confirmed novel predictions but because it the theorem can be grasped intuitively by an experienced person and deducible by axioms. Reading 3 Confirmation Reasoning -Example: Einstein's Theory of General Relativity -When predictions based on a theory becomes correct, it provides some evidence that the theory is correct. -It is a type of inductive reasoning. Thus, it will not gurantee the conclusion. Discomfirmation Reasoning -Example: Cold fusion theory -When predictions based on a theory becomes wrong, it provides some evidence that can be used against it. -It is a type of deductive reasoning. -Discomfirmation reasoning involves having a number of auxiliary hypotheses. It shows either the theory in question is wrong or one or more of the auxiliary evidence is wrong. Inductive Reasoning -All premises can be true but it is still possible for conclusion to be wrong. Deductive Reasoning -True premises can guarantee a true conclusion. Quine-Duhem thesis -That it is impossible to test a scientific hypothesis in isolation, because an empirical test of the hypothesis requires one or more background assumptions. The hypothesis in question is by itself incapable of making predictions. Instead, deriving predictions from the hypothesis typically requires background assumptions that several other hypotheses are correct. Falsificationist approach -Popper thinks that science should emphasize on falsification over confirmation and should strive for at-risk theories. LECTURE 4- Law or no Law? Is scientific change a rational (law-governed) process? YES -Changes in methods are due to changes in accepted theories. Our methods evolve as we learn now things. Example: Drug testing methods changed in order to provide the mos
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