Notes For Philosophy Of Science

I. Basic model of scientific method usually taught: C make observations C record data C classify data by subject C induce general laws from experiments C make specific predictions C make new observations Very limited. Distorts what science really is. Works reasonably well for day-to-day analysis. II. How do chemists (scientists) conduct themselves? C May or may not work alone in a lab. C Mostly a group effort in a lab (many names on an article). C Constant interatction with other membors of the profession: face-to-face, phone, e-mail, meetings, journals. Ideas are freely exchanged. This often makes it difficult to pin down who thought of what first. Beware of individuals out of the mainstream working alone. C Time is relatively unimportant: personal activities and money often secondary to basic research. C Scientists constantly generate theories and test them in the lab. Theory and experiment deeply intertwined. C Try to keep open mind and have willingness to abandon bad theory. III. Scientific Paper: C A written paper is submitted to an appropriate journal. C It undergoes peer review. The editor sends article to recognized experts in the field who look for relevance, clarity, inconsistencies, or omissions. C It is sent back with suggestions for revision and possible additional experiments. C Authors generally follow enough suggestions to get article published. Article itself: C Each journal has basic guidelines as to content and structure. C Where it is being submitted from. C Number of authors and their names. C When received and when published. C Abstract- A mature science has articles incomprehensible to non practitioners. C Invariably, there is previous research in the field discussed. Relevant articles are cited and the stage set for why authors carried out present work. C Theory and results completely intertwined. Fundamentals of a science agreed to by its members. Most science is involved in using basic theories to extend knowledge and fill in blanks of fundamentals. C Basic theory provides a general framework. Dissension of details is common. C Summary of most important conclusions.

IV. Basic Research: Discovering without any application in mind. Development: Application of research to a problem Technology: Results of development. R & D have a synergistic effect on one another. Fundamentals Electromagnetic Theory

→

Application Radio, TV

Solid State (quantum mechanics)

Transistor, Laser

Electromagnetism

Battery (theory independent)

Astronomy

Clock, Lens (theory independent)

(Newtonian Mechanics)

Steam Engine

Thermodynamics Without one, the other is seriously hampered. Unfortunately, you never know what line of basic research will be fruitful. There is also an annoying lag between basic research and its eventual application Limitations and Possibilities: C Science attempts to describe the working of the universe by observing a limited part of it. E.g. experiments in lab. C Claims are made about things which cannot be observed. E.g. atoms, electrons, orbitals C It says nothing about the value of a human being, political ideology, art or moral values. Beware of those who try to peg such a judgement on a theory, irrespective of whether the guidance is pro or con. Texts present scientific method as well as a culture is represented by a tourist brochure. Paradigm: A set of fundamental theories of a given science. E.g. chemistry: atomic theory, quantum mechanics The simple idea of how science works says we deduce predictions from theory which is then checked. If the theory predicts something which turns out to be wrong, then part or all of the theory is wrong. E.g. World will end 4/8/01.

Theory thus must: C Make predictions C Have observable consequences C Be limited in scope so as not to include any possibility A theory must also be falsifiable. This means a theory is not necessarily false, it just means it can be tested. Logic of scientific theories: C If it is raining, the streets are wet. C The streets are wet. C Therefore, it is raining. Logic Blunder! Streets could be wet for other reasons: melting snow, street cleaning, broken water pipe. Galileo first used this type of logic: C If the planetary system is heliocentric, Venus will show phases. C Venus shows phases C Therefore the solar system is heliocentric Galileo was ultimately brought before the Inquisition not for heresy, but for calling a sun centered system as proved using a logic which denies absolute proof. Thus, the paradigm can be falsified but a particular theory can never be proven absolutely true. Galileo’s reasoning produced interesting consequences which gives this method great power. C If the earth is just a planet, then other planets might be similar to earth. C Heliocentric system much simpler than Ptolemy’s system. C Satellites of Jupiter are like a miniature solar system. Notice that items 1 and 3 could have lead to falsification Science now has these characteristics: C It does not consist of a body of demonstrated truths. C Fallibility is a hallmark of science. C Paradigms used at one point can be replaced by another because of evidence. E.g. Newton thought light was made of particles. In the early 19th century wave explanation displaced older paradigm. In early 20th century light paradigm became something else with both particle like and wave like characteristics. C Thus science is not a linear progression of theory-experiment-theory. C Sharp discontinuity between paradigms. C Results of experiments done today could be called into serious question in the future.

Different theories have different likelihood for being correct. Given time, it is possible to distinguish between them (Occam’s Razor) No theory 100% perfect. A theory gains credibility when it makes successful predictions. E.g. Air is like an ocean. Prediction: Air pressure should decrease with altitude. Theories presented in textbooks tend to be unfalsifiable. E.g. Apple breaks off branch but does not fall. Any behavior of the apple can be explained by suitable application of laws of motion. A theory cannot be tested individually. Theories must be tested in bundles. E.g. Nature of bacteria being observed using electron microscope. Another e.g. Dinosaurs wiped out by meteor- existence of isotopes, operation of mass spectrometer (electronics, magnetism), geologic stratification, radioactive decay. Rather large bundles must be tested. If results don’t match prediction, then a member of the bundle has problems. Different bundles can be tested. Science is heavily intermeshed. The fact that testing different bundles of theories yields consistent results gives these theories a high confidence rating. Any single theory can be wretched from context and proven to be unscientific. What then is successful science? E.g. Newtonian Mechanics C Explained position of planets except for Uranus. C Abandon Theory? C No! Use auxiliary hypothesis C Auxiliary Hypothesis- There exists an unknown planet affecting Uranus. The location and orbit was quantitatively computed. Existence of this proposed planet could be tested independently from the main theory (bundled with optical theory). Newtonian mechanics is a unified theory. It consists of a small set of problem-solving strategies which can be used in a wide variety of problems: C Motion of celestial bodies C Motion of projectiles C Motion of tides C Motion of pendulum oscillations Another example: Quantum Mechanics. It’s problem-solving strategies can be applied to: C Emission Spectra (Bands within a line, line intensity, line bandwidth) C Magnetism C Color of Solids C Electrical Conduction C Photography

A science (paradigm) is a unified whole, not a patchwork of ad hoc assumptions. Fecundity (fertility): Successful science often generates new sciences. E.g. evolution C taxonomic classification C immunology C population genetics C molecular biology C social behavior Summary: Successful science consists of three major characteristics 1. Independent Testability- Auxiliary hypothesis must be testable independently of the principle theory. 2. Unification- A small group of problem-solving strategies which can be applied to a broad class of cases. 3. Fecundity- Incompleteness in a theory which gives rise to valuable new lines of investigation. The basic method normally taught in book is a part of science, but it is only a snippet out of a larger whole.