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Page 1: math 195.1 - Weebly

http://jfratup.weebly.com/math-195-2016-2017.html

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MATH 195 Part 1Science

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What is science?• Formal Sciences• Natural Sciences (physical sciences and life sciences)• Social Sciences

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HISTORY

Aristotle: Deductive Logic

(384– 322 BC)

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“The problem with deductive logic is that the conclusion of a deductively valid argument cannot say more than is implicit in the premises.

…although where the argument is complex we may find the conclusion surprising just because we hadn’t noticed that it was already implicit in the premises”

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HISTORY

Francis Bacon: InductionOr Confirmation

(1561– 1626)

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“Inductive reasoning, or induction, is the name given to various kinds of deductively invalid but

allegedly good arguments”.

“The idea is to reach the truth by gathering a mass of information about particular states of affairs and building from them step by step to reach a general

conclusion”.

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•Empirical observation, data gathering, experiments…

•Experiments: test all possible controlled cases (e.g., by elimination, trial and error). Experiments allow us to ask ‘what would happen if?’

•Experiments should be repeatable, so that others can check the results.

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Experiments• in vivo: done inside the living organism

• in vitro: done outside the living organism

• in situ: done where organisms are found in nature

• in silico: done on computer (computer simulation)

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Theoretical vs Empirical

“Empirical observation and experiment is a neutral foundation for scientific knowledge, or at least for the testing of scientific theories”.

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• “Induction is justified by the theory of probability”. Frequentist and Bayesian statistics

• “Scientific knowledge is objective means that it is not the product of individual whim, and it deserves to be believed by everyone, regardless of their other beliefs and values”.

• “Observation without any bias whatsoever is impossible”.

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Major Problem of Induction• “Bertrand Russell (1872–1970) famously argued in the Problems

of Philosophy, sometimes inductive reasoning may be no more sophisticated than that of a turkey who believes that it will be fed every day because it has been fed every day of its life so far, until one day it is not fed but eaten”.

• Problem of Extrapolation: “in the past the future has been like the past doesn’t mean that, in the future, the future will be like the past”.

• “It is for this reason that the philosopher C.D. Broad (1887–1971) called induction the glory of science and the scandal of philosophy”.

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But well…

• “Inference to the best explanation, which is sometimes called abduction, is the mode of reasoning that we employ when we infer something on the grounds that it is the best explanation of the facts we already know”.

• “In science, hypotheses are often adopted because of their explanatory power”.

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Question“Most people use induction and those that don’t are mad

and you can’t reason with them. What makes you think you’re the sane one”?

“Good about science is an attitude of scepticism towards the traditional dogma”

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HISTORY

Karl Popper: Falsification

(1902–1994)

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“deciding whether something is scientific or not will often be a decision with significant consequences

for people’s lives”

• “It is just too easy to accumulate positive instances which support some theory, especially when the theory is so general in its claims that its seems not to rule anything out”

• Falsificationism: “grounds for the demarcation of science from non-science (fringe science, pseudoscience and junk science)”

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• “Popper came to the view that it is not confirmation but falsification that is at the heart of the scientific method”.

• “No matter how many positive instances of a generalisation are observed it is still possible that the next instance will falsify it”.

• “The inference from a falsifying instance to the falsity of a theory is purely deductive”.

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• “Once a hypothesis has been developed, predictions must be deduced from it so that it can be subjected to experimental testing”.

• “If it is falsified then it is abandoned, but if it is not falsified this just means it ought to be subjected to ever more stringent tests and ingenious attempts to falsify it”.

Popper was particularly impressed by the experimental confirmation of Einstein’s general theory of relativity in 1917.

Note: there is no distinction between scientific theories, laws, principles, etc.

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Method of conjectures and refutations

• “this is the way in which we can learn from our mistakes; and that in finding that our conjecture was false we shall have learnt much about the truth, and shall have got nearer to the truth” – Popper

• “theories that in their time were considered highly confirmed and which enjoyed a huge amount of empirical success, have been shown to be quite mistaken in certain domains”

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So can we ignore non-scientific beliefs?

• “It is perfectly possible for someone with religious faith and beliefs to accept a definite demarcation between science and religion (this may be the case with many scientists)”.

• But non-scientific beliefs can be a source of discovery!

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The context of discovery

• “Generation of scientific theories is not, in general, a mechanical procedure, but a creative activity”

• “Scientists may draw upon diverse sources of inspiration, such as metaphysical beliefs, dreams, religious teachings and so on, when they are trying to formulate a theory”.

• “The kind of speculation and imagination that scientists need to employ cannot be formalised or reduced to a set of rules. In a way this makes the sciences closer to the arts than they might otherwise seem. On the other hand, the sciences differ from the arts in being subject to testing by experience and this must be the final arbiter of any scientific dispute”.

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Studying history of Science

“In Popper’s view then, there are two contexts in which we might investigate the history of science and the story of how certain theories come to be developed and accepted, namely the context of discovery and the context of justification”.

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Some legitimate parts of science seem not to be falsifiable

• “Statements that assert the existence of something cannot be falsified by one’s failure to find them”

• Sometimes we need to visit the past or need to investigate evolutionary timescales

• “Falsificationism is not itself falsifiable: it is a philosophical or logical theory of the scientific method, and not itself a scientific theory”

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What could happen

• “Instead of abandoning a theory, scientists thought up modifications or extra assumptions to save it”.

• “Where scientists have a successful theory, the existence of falsifying observations will not be sufficient to cause the abandonment of the theory in the absence of a better alternative”.

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Bacon + Popper: Science is about confirmation as well as falsification

• “Science is cumulative. In other words, scientists build on the achievements of their predecessors, and the progress of science is a steady growth in our knowledge of the world. This feature of science is sharply contrasted with other activities, such as art, literature and philosophy, which are progressive in a much looser and controversial sense”.

• “Science is unified in the sense that there is a single set of fundamental methods for all the sciences, and in the sense that the natural sciences at least are all ultimately reducible to physics (Reductionism)”.

• “Scientific terms have fixed and precise meanings”.

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HISTORY

Thomas Kuhn: Paradigm

(1922–1996)

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Kuhn’s ‘paradigm’

• “If a new paradigm is adopted by the scientific community, then a ‘revolution’ or ‘paradigm shift’ has occurred”.

• “Kuhn also emphasises the role of psychological and sociological factors in disposing scientists to adopt or a reject a particular paradigm. Some people are inherently more conservative than others, while some enjoy being a lone voice in the wilderness; some people are risk takers and others are risk averse, and so on”.

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MISUNDERSTANDING?

• Terms and concepts of scientific theories in different paradigms are not mutually intertranslatable; this is called meaning incommensurability (lack of common measure).

• A simple form of epistemic relativism would say that, for example, a particular theory in physics or biology might be counted as knowledge just because it was believed by those with status and influence within the community of physicists or biologists.

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Kuhn’s five core values common to all paradigms

• A theory should be empirically accurate within its domain.

• A theory should be consistent with other accepted theories.

• A theory should be wide in scope and not just accommodate the facts it was designed to explain.

• A theory should be as simple as possible.

• A theory should be fruitful in the sense of providing a framework for ongoing research.

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MATH 195 Part 2Mathematics

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Problem of Reductionism (my own point-of-view)

Philosophy ❤ Logic ➡ Math

Math ❤ Computers ➡ Computer Science

Philosophy ❤ Math (Language & Queen of Sciences) ❤ Reality ➡ Science

Physics ❤ Matter ➡ Chemistry

Physics ❤ Chemistry (the Central Science) ❤ Life ➡ Biology

Biology ❤ Behavior & Mind ➡ Psychology (note: brain is not equal to mind)

Psychology ❤ Human interaction ➡ Social Science

Social Science ❤ Wealth ➡ Economics

Science ❤ Technology ➡ Engineering (a bit of everything?)

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Philosophy ❤ Logic ➡ Math

Math ❤ Computers ➡ Computer Science

Philosophy ❤ Math (Language & Queen of Sciences) ❤ Reality ➡ Science

Physics ❤ Matter ➡ Chemistry

Physics ❤ Chemistry (the Central Science) ❤ Life ➡ Biology

Biology ❤ Behavior & Mind ➡ Psychology (note: brain is not equal to mind)

Psychology ❤ Human interaction ➡ Social Science

Social Science ❤ Wealth ➡ Economics

Science ❤ Technology ➡ Engineering (a bit of everything?)

Note: this is just a crude representation of the branches of science. The distinctions between branches are vague in the modern perspective.

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What is maths?• Theoretical or Pure Math• Applied MathBut there is no clear line separating the two…

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Maths

•Study of patterns

• “Mathematicians seek truth, beauty and elegance” (Math Institute , Oxford U)

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https://s-media-cache-ak0.pinimg.com/236x/33/db/eb/33dbeb3c7e0b5f052ff1064e42e91740.jpg

https://bookofresearch.files.wordpress.com/2015/02/pareidolia3.jpg

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“Science of patterns” (Sir Cortez)================================

From friend Wiki:

“Mathematicians seek out patterns and use them to formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical

proof (e.g., by deductive logic)”.

“When mathematical structures are good models of real phenomena, then mathematical reasoning can

provide insight or predictions about nature”.

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Abstraction

“The first abstraction was probably that of numbers: the realization that a collection of two apples and a collection of two oranges (for example) have something in common, namely quantity of their members”. –wiki

“Abstraction in mathematics is the process of extracting the underlying essence of a mathematical concept, removing any dependence on real world objects with which it might originally have been connected, and generalizing it so that it has wider applications or matching among other abstract descriptions of equivalent phenomena”. –wiki

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From other colleagues:

•Sir Egarguin: anything that can be learned (coming from the original Greek word μάθημα or máthema which means “knowledge, study, learning”)

•Sir Palines: a language that only few dare to understand

•Sir Marasigan: “course ko”

•Maam D. Cuaresma: greatest discovery of all times (used implicitly or explicitly in all disciplines)

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Summary of keywords

• Patterns to Conjectures to Theorems

• Proof, Deductive logic

• Abstraction

• “Elegant” Language

•Model of real phenomena, Tool in problem solving

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The worlds of Mathematics: Axiomatic Systems

An axiomatic system consists of some undefined terms (primitive terms) and a list of statements, called axioms or postulates,

concerning the undefined terms. One obtains a mathematical theory by proving new statements, called theorems, using only the

axioms (postulates), logic system, and previous theorems. Definitions are made in the process in order to be more concise.

“Axioms in traditional thought were ‘self-evident truths’, but that conception is problematic”. -wiki

http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm

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The worlds of Mathematics: Axiomatic Systems

“It is crucially important in a proof to use only the axioms and the theorems which have been derived from them and not

depend on any preconceived idea or picture”.http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm

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The worlds of Mathematics: Axiomatic Systems

“An axiomatic system is consistent if there is no statement such that both the statement and its negation are axioms or

theorems of the axiomatic system”. (No Contradictions)

“Contradictions in the real world are impossible. If we exhibit an abstract model where the axioms of the first system are

theorems of the second system, then we say the first axiomatic system is relatively consistent”.

http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm

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The worlds of Mathematics: Axiomatic Systems

“An axiom is independent if it is not a theorem that follows from the other axioms. Independence is not a necessary

requirement for an axiomatic system; whereas, consistency is necessary”.

http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm

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The worlds of Mathematics: Axiomatic Systems

“An axiomatic system is complete if for every statement, either itself or its negation, is derivable in that system”.

“Kurt Gödel (1906–1978) with his Incompleteness Theoremdemonstrated that even in elementary parts of arithmetic

there exist propositions which cannot be proved or disproved within the system”.

http://www.newworldencyclopedia.org/p/index.php?title=Axiomatic_systems&oldid=995784 http://web.mnstate.edu/peil/geometry/C1AxiomSystem/AxiomaticSystems.htm

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Theorem Environment“The concept of a theorem is fundamentally deductive, in contrast to the notion of a scientific law, which is experimental” - wiki

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Theoretical Math(“study for the sake of math”)

A naïve way of classifying maths:

• Foundations of Math (e.g., Logic, Set Theory)

• Algebra and Combinatorics (“structure”; e.g., Abstract Algebra, Combinatorics, Number Theory)

• Analysis (“change”; Calculus, Real Analysis, Complex Analysis, Functional Analysis, Differential Equations, Dynamical Systems)

• Geometry (“space”; e.g., Trigonometry, Synthetic and Analytic Geometries, Euclidean and Non-Euclidean Geometries, Projective Geometry, Discrete Geometry, Topology, Manifold Theory)

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Applied Math(“math intended for use in other disciplines”)

Examples (some here are still considered theoretical math):

• Probability and Statistical Theory

• Actuarial Science

• Computational and Numerical Mathematics

• Theoretical Computer Science (including Automata Theory, Coding Theory & Cryptography, Machine Learning, etc.)

• Mathematical _______ (Physics, Biology, Chemistry, Social Science, Finance, Economics, etc.); Mathematics of Complex Systems

• Operations Research, Optimization and Control Theory

• Recreational Mathematics

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Theoretical and Applied Maths differ on their FOCUS

but there is no demarcation line between them

Theoretical Math

Application Area

Spectrum of Applied Math