Chapter 13.

Structure of Newtonian Science

13.1. Physical Concepts

• Physical concept - general idea, notion, or understanding derived from specific occurrences in natural world
• Use of concepts
  • Reference frame for understanding
  • Medium for discussion and argument
  • Elements from which laws and theories are composed
• Characteristics of concepts
  • Defined operationally, i.e., prescribed series of actions whereby concept or physical quantity can be measured
  • Quantitative nature, i.e., nature works according to mathematical laws and observations are explained by mathematical laws relating observable quantities
  • Mathematical concepts, i.e., those taken from mathematicised world of ideal and precise objects, realm in which actions exist as calculations
  • Used in variety of fields
• Operational definitions
  • Specialized and specific vocabulary which requires rigorous use
  • Permits use of concept whose "reality" is unknown
  • Errors, do not mean wrong or mistaken-not moral judgment; errors are departures from exactness
  • Primary concepts, those not definable operationally relegated to secondary

13.2. Creativity in Science

• Creativity not a prescription for scientific progress
• Scientists do not worry about methodology, in general, unless problems arise
• Scientist may make provisional hypotheses or be guided by
  • A "feeling for things"
  • Analogy with other situations
  • Promising guesses
  • Trial and error
• No limitations placed on scientific thinking until such time as ideas are presented to public science
• Process of discovery - facets that have in part lead to discovery
  • Intuitive feeling for nature, particularly for quantitative aspects
  • Using one's intelligence to utmost with common sense
  • Awareness of landscape out of which particular problem arises
  • Reliance on observations and experiment to resolve issues
  • Foreknowledge of type of solution to be expected
  • Sensitivity for recognizing favorable though unexpected turn of events
  • Never pretending to explain phenomena with absolute finality

13.3. Scientific Theories

• Role of theories
  • Correlate many separate and possibly diverse facts into logical, easily grasped structure of thought
  • Stimulate imagination
  • Force predictions of new measurable or observable events
• Characteristics of successful theories
  • Based generally on few simple assumptions or hypotheses
  • Hypotheses hopefully testable
  • Flexible enough to grow and be modified
  • Leave successors and not shambles when they die
• Role of scientific models
  • Mental picture, idealization, based on physical concepts and aesthetic notions that accounts for what we observe; model allows predictions of future course for phenomenon
  • Ancient organismic models, possess attributes of living organisms
  • Mechanistic models, from Newton on science used mechanical models
  • Mathematical models, science increasingly resorts to mathematical models which may have no mechanical basis
  • Examples: Newtonian gravity, Bohr model of atom, Solar System model, models for stars, galaxies, etc., cosmological models
• Newton's rules for reasoning
  • Parsimony - "...admit no more causes of natural things than such as are both true and sufficient to explain their appearances"
  • Cause and effect - "...to the same natural effects we must...assign the same causes."; cause produces effect, but effect does not produce cause (irreversible nature of time)
  • Universal qualities - "...all bodies within the reach of our experiments, are to be esteemed the universal qualities of all bodies whatsoever."
  • Induction (Kepler) - "...look upon propositions inferred by general induction from phenomena as accurately or very nearly true...till such time as other phenomena occur, by which they may either by made more accurate, or liable to exceptions."
• Role of scientific laws
  • Rules, preferably mathematical, by which we believe nature operates; classification:
  • Empirical, general statement identifying regularity in observations with no cause-effect explanation; example: Kepler's laws
  • Definitional, definition of fundamental concept; example: Newton's 2nd law of motion (force = mass x acceleration)
  • Derived, derived from some underlying theory; example: Newton's law of gravitation (derived from Kepler's laws, Newton's laws of motion, and concept of action-at-a-distance)
• Explanation in science
  • Science explains by making unfamiliar familiar; establishing relationships between unfamiliar and familiar or preconceptions
  • Larger goal is to explain intricacies of nature as rationally and coherently as possible; discovering mathematical laws between observable quantities
  • How do scientists find explanation by discovering mathematical laws?
    • Aid utilization
    • Provide control
    • Point direction
  • Human tools for understanding physical phenomena are pictures, allusions, and analogies involving primitive events of everyday life that dwell in our imaginations
  • As science ponders problems far removed from common experience
    • Necessary to supplement mental tools with which we grasp and comprehend
    • Because of break down in more naive types of understanding that insist on intuitive, visualizable explanations
    • Increasingly mental tools are mathematical concepts and laws
• Definition of theory
  • Conceptual scheme invented or postulated in order to explain observed phenomena and relationships between them
  • Brings together in one structure observations, concepts, hypotheses, and laws
  • Unifies, and in so doing simplifies
  • Assumed to have universal applicability when it agrees with what we already know and can be repeatedly validated by future experiments, observations, or experiences to which applied
  • Where do theories come from?
    • Suggested by examination of data
    • Product of imagination in which the mind has been stimulated by data
    • Arises from combination of observation and imagination
  • No answers to such questions; no consensus among scholars even

13.4. Reality in Science

• Does science capture reality?
  • Equivalent to asking which philosophy, realism or idealism, characterizes what theories reveal
  • Realism (Aristotle), belief that experiences that come by way of our senses must reveal a "real" world that exists independent of any human perceiver or acts of perception
  • Idealism (Plato), belief that there is no objective or absolute reality apart from products of our imagination or mental constructs