SCIF Study Notes - David Ellyard

SCIF Study Notes - David EllyardWhat is science? A body of knowledge, a process, an enterprise, an attitude.Science is a body of knowledge/understanding, a process (continual proposal, testing and reviewal), an enterprise (something we collectively strive for), and an attitude (believing that this is attainable, and in the fallibility of experts). It is not an unchanging compendium (collection of concise detail) of truthful statements, nor an unwavering, step-by-step to the truth, cannot solve all human problems (as scientism would be believe), completely objective, free of ideology or belief, nor the work of a few. There are three Ps - process, paradigm and precision.Characteristics of science

human in both nature (could be mistakes) and purpose (for our own personal desires) curiosity-driven

contemplative

cumulative (and therefore exponential)

tentative/never settled/no final truth

evidence-based

open to challenge/self-correcting

sceptical (hard to convince)

subjective (not objective, but strives for this)

systematic/methodical (but not an wavering, step-by-step jouney)

What benefits does science deliver?

satisfaction of human curiosity, possibly from evolution: Patternism - tendency to seek patterns/regularities in random, unconnected events

Agentism - tendency to think some cause or agent is at work, causing a pattern

development of technology (improves life quality/quantity)

provides work for scientists

improves chances of survival with an understanding of the world

Definitions of the Process of ScienceData - information about some phenomenon by experiment and observation (generally quantitative by readings of measurements that amplify/quantify sense impressions); data are the only facts in science (hypothesis/conclusions/other conjectures are all derived from data), although are still fallibleHypothesis - from Greek hypotithenai (underlying argument or idea), it is a tentative explanation for existing data (from observation), and can be used to generate predictions for testingTheory - from Greek theria (contemplation), it is a hypothesis that has survived some testing, and the more tests it passes, the more it can be relied upon and the more useful it becomes; however, they are never definitively proven, just not wrongObservation - (incorporates experiment) pure observation accepts data that nature provides (sometimes with filtering) Experiment - (active observation, some aspect of nature is simulated and its response noted) involves abstraction (some influencing factors are controlled)Induction - generating a hypothesis (model) from a specific set of data by methodically observing regularities (particular general); cant ever be sure if your interpretation is correct, hence not very reliable, e.g. all swans are white because all swans Ive seen are whiteDeduction - generating predictions from a hypothesis for testing by further experiment (general particular); more reliable as it is constantly tested, e.g. mathematical induction OR all men are mortals, Socrates is a man, Socrates is a mortalThe Weakness of Induction and Poppers FalsificationHume (and others) argue induction cannot ever be completely correct as no amount of empirical evidence can conclusively prove a hypothesis, but one conflicting observation can falsify it. They are not proofs, but only one possible explanation for data, but can be more probable with evidence of increased volume AND strength. Most hypotheses come from hunches, speculation and imagination rather than methodical induction.Karl Popper (1902-1994) published The Logic of Scientific Discovery (1934), stating, Our knowledge can only be finite, while our ignorance must necessarily be infinite. which means the more we know, the more we realise we dont know. He also said, Science may be regarded as the art of systematic over-simplification. He believed hypotheses were conjectures to explain observed data, the bolder the better (those that ran counter to accepted views or prima facie (first impressions) of senses (like Copernicus opposing heliocentric view; these people are considered part of Poppers heroic science). They are then subjected to refutation to be proven wrong, the more severe the better. The most that can be said about a hypothesis is that is has survived testing better than alternatives.He also believes for a statement to be scientific, it must be falsifiable (at least in principle - you must be able to conceive some form of evidence that would render the statement incorrect), and hence Marxism (which was originally believed to be scientific and his since been disproven as capitalism has not lead to misery and complete revolution, nor did this revolution occur in advanced societies), Freudianism, astrology nor creationism can be considered scientific as they do not admit to the possibility of being wrong. It is also hard to falsify complex hypotheses as they could be wrong for many reasons, and finding which it is becomes tricky.Popper also believes that reality has many layers (as opposed to positivism/phenomenalism - only sense impressions exist and objects are permanent associations of these, realism - there are real objects independent of an observer), aligning himself with instrumentalism (doesnt deal with objective reality, but rather that theories are used to understand the world with an emphasis on prediction and problem solving; attraction is that it works) and hence the concept of black boxes (reality has many layers, sense impressions being the outermost, but underlying causes/agents working to make these; e.g. the gene causes the whole human body, but it itself is made of molecules, and so on).Characteristics of a good:

Experiment Focused on testing clear hypothesis Provides numerical results to check against predictions from hypothesis

Factors not investigated are controlled or excluded

Minimises systematic error Minimises impact of observer Maximises objectivity (eliminates confirmation bias - giving explanations to support your own hypothesis when results say otherwise and not considering other hypotheses) Well-documented, hence repeatableHypothesis Plausible explanation for existing data, as well as or better than rivals, including data not otherwise explained Generally fits with current understanding/paradigms, though it may advance new concepts/entities

Introduces as few new entities as possible (attraction of simplicity/Occams Razor)

Mathematically elegant/appealing (it works)

Able to be tested (more ways the better - increases fruitfulness)

Simplicity in Science - Occams RazorWilliam of Ockham (1287-1347) states Plurality should never be posited without necessity, basically stating to choose the simpler hypothesis, which forms the basis of Occam/Ockhams Razor. However, this idea was suggested several times before him, notably by Ptolemy (we consider it a good principle to explain the phenomena by the simplest hypothesis possible) and Aristotle. Einstein later said, Everything should be made as simple as possible, but no simpler. However, the simplest may prove wrong (carrier of genetic information was DNA, not the simpler hypothesis of it being proteins).

Quality Control in Science Hypotheses are based on repeatable experiment Results/hypothesis are (often) openly and freely published, including details of method

Allows publication to be subject to peer review - but this is still subject to error Could possibly stifle dissent/disagreement - evident in past paradigms

Bacons DictumNature to be commanded must be obeyed

To use/command nature (i.e. advance technology) we must understand how it work first or obey its laws in our imaginations as well. E.g. to get to the moon we cant use a balloon as Cyrano de Bergerac wrote (no atmosphere), nor by firing a large cannon with a space capsule as Jules Verne wrote (g forces, lots of energy at once). Hence to control nature, we must know how it works. For knowledge itself is power.

Francis Bacons (1561-1626) Four IdolsImpediments of growth and spread of knowledge (idols=false images): Idols of the Tribe - tendency to see what we expect to see and evidence to support conclusions already reached (confirmation bias, but also how science originated)

Idols of the Cave - differences in individuals based on upbringing and experiences (leading to likes and dislikes, preference of novelty vs. antiquity)

Idols of the Marketplace - words in common use have different meanings in science (e.g. hypothesis - actually is current best explanation)

Idols of the Theatre - incorrect perceptions from stage-plays (false stories) of philosophical/religious/ideological tradition

Kuhn and Paradigms

Thomas Kuhn (1922-1996) wrote Structure of Scientific Revolutions (1962), stating that science progresses through better data and more inclusive theories and models (terrestrial and celestial physics - Newton; magnetism and electricity - Faraday; electromagnetism and light - Maxwell; waves and particles (Young, Einstein); mass and energy - Einstein). Paradigm - a dominant/pre-eminent framework or world view in a given area of science, determined by consensus among practitioners in a given field (challenged at most by a minority). They influence the interpretation of new evidence, guiding further investigation in a particular direction. Examples include:

stars are living creatures

heavens dictate our lives

everything is made of atoms and the void

aether model - nature abhors a vacuum

disease is caused by miasmas

living things have a spirit (differentiates them from non-living)

all life comes from life

all living things are made of cells (viruses perhaps?)

geocentrism (supported by Aristotle, Ptolemy, church, common sense until 17th C) vs. heliocentrism (ancient Greeks, Brahe and Keplers measurements, Copernicus - explained retrograding, and used simple circular orbits instead of epicycles to explain changing planet sizes and speeds and accounted for Galileos observations of Jupiter and Venus, took over a century to be accepted, later modified with Keplers elliptical orbits, Newtonian physics (explained how it worked)); we now believe the universe has no defined centre paradigm of the four (or three elements) - all matter consisted of earth, fire, water and air (ancient Greece; explained movement/natural motion - earth and water had gravity, air and fire had levity) or salt, sulphur and mercury (Islamic medieval alchemists; not our current elements); lasted until 17th C when Robert Boyle gave a modern definition of an element in The Skeptical Chemist, and Newton later explained the forces

paradigm of the fiery stuff (phlogiston) - everything that burns contains phlogiston and released it when heating; metals formed an oxide they called calx which they believe was evidence of phlogiston; believed we would eventually run out of phlogiston (as burning in enclosed space eventually died), and until the 18th C there was a belief that H2 was phlogisticated air (or even pure phlogiston), and O2 was dephlogisticated air (it would only burn once a smouldering splinter was added to it); countered by rise of precise measurement (paradigm would require negative weight as burning increased mass (oxide formed), and replaced by combustion/calcination due to combination with O2 by Lavoisier paradigm of four humours - influential until 18th C with the rise of scientific medicine, and impacted by Harveys circulation of blood discovery (blood was believed to have moved like tides or be created and destroyed, but Harvey said more blood would have to be made than food consumed and established primary of blood over humours (when they were allegedly equal), but his own hypothesis required the discovery of capillaries with microscopes to be accepted)

Paradigm Shift - a fundamental change in approach or underlying assumptions; replacement by or incorporation into (subsumed) a more complete framework when the current paradigm cannot deal with the broad range of evidence (and most paradigms ultimately prove inadequate)Kuhns Three Phases of Science: Prescience - no accepted paradigm to guide investigation

Normal Science - existing paradigm is not challenged but rather extended in range of application or made more precise (what scientists do most of the time) Revolutionary Science - overthrowing the existing paradigm in a paradigm shiftEpistemology and Thought ExperimentsThe men of experiment are like the ant, they only collect and use; the reasoners resemble spiders, who make cobwebs out of their own substance. But the bee takes the middle course: it gathers its material from the flowers of the garden and field, but transforms and digests it by a power of its own. Not unlike this is the true business of philosophy (science); for it neither relies solely or chiefly on the powers of the mind, nor does it take the matter which it gathers from natural history and mechanical experiments and lay up in the memory whole, as it finds it, but lays it up in the understanding altered and digested. Therefore, from a closer and purer league between these two faculties, the experimental and the rational (such as has never been made), much may be hoped. - Francis Bacon (early 17th Century)Epistemology (study of knowledge) is split into two broad answers:

Rationalists - the general nature of the world can be established by thought alone as the mind has inherent (a priori - prior/before) concepts not derived from experience (e.g. Euclidean geometry, Descartes - a vacuum is repugnant to reason) - equivalent to a spider

Empiricists - genuine knowledge comes from experience (ultimately sense impressions), and can lead to scepticism of the existence of a real world (a posteriori - post/later; e.g. David Hume - a wise man proportions his belief to the evidence) - equivalent to an antEmmanuel Kant proposes a third way: knowledge has two sources, both intellect and senses, the former providing the tool to order the sense impressions (e.g. concepts of time, space, substance, causality, categories) - equivalent to the bees.Galileo was one of the first to use thought experiments, disproving Aristotles theory that heavier objects fall faster when subjected to gravity by imagining a heavy ball and a light ball connected by a string being dropped. Theoretically, the heavier ball would fall faster than the smaller ball, causing the string to go taught, and tension pulling the smaller ball down, but the heavier ball up. However, as the whole system is heavier, it should fall faster, not slower. Hence heavier objects cannot fall faster.The Role of Measurement in ScienceRoger Bacon (13th C) stated, this world cannot be made known without a knowledge of mathematicsall this information is secured by means of instruments Similarly Galileo (17th C) said, Philosophyis written in the mathematical languagewithout the help of which it is impossible to conceive a single word of it... Stephen Hales (18th C), Humphry Davy (19th C), Lord Kelvin (19th C) and Francis Galton (19th C) said similar things.

Modern science progresses by quantifying (not observing and classifying), with new measuring instruments and methods generating new knowledge. Galileo invented the pendulum clock (noticed a period is only dependent upon length and strength of gravity, not pendulum mass/nature or speed, compared to pulse and found it was constant - isochronism). Helped define shape of Earth (swings more slowly near Equator) and that the Earth turns (Foucault).Sanctorio (the first medical scientist) invented a pulsilogium (varied length of pendulum to patients pulse, quantified it), a thermometer (blowing would heat air to your body temperature, which would push wine back down a numerically-marked tube), and weighed everything that went in and out, finding more went in than out, and there must be invisible perspiration (idea originally from Galen).

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Oliver Bogdanovski