Unit 3 - How Does Science Proceed? Flashcards
Describe some of the factors that motivate people to engage in scientific activity.
The capacity to wonder, the desire to understand, and the desire for truth.
(Of course, the desire for money or prestige can also play a greater or lesser part for some individuals).
Discuss science as a guided process of questions and answers.
Science is a particular form of guided questioning.
The philosopher Karl Popper (1902-1994) labeled this process as one of “conjectures and refutations.” A conjecture is made, and the scientific community attempts to refute it, leading to a progressive sharpening and refinement of the original conjecture. But before a scientist can make a conjecture, he or she must have a question that the conjecture is intended to answer, and this gives rise to a new set of questions: How well does the conjecture answer the initial question? Is it consistent with currently accepted theory? Does it correspond to the facts?
In Kuhn’s view, an existing scientific “paradigm” (i.e., the basic set of assumptions and beliefs guiding development in a scientific discipline, hence providing the context for asking significant questions) raises questions of consistency and empirical fit, and it is assumed that it is possible to construct answers to these questions (puzzles) within the assumptions that define the paradigm. Only in extreme cases, where a set of central questions have gone unanswered for a long period of time, is the paradigm itself questioned. When this occurs, the field of potential questions and answers widens and a scientific revolution begins, eventually resulting in the emergence of a new paradigm within which the previously unanswered questions of the old paradigm are either answered, or seen to be irrelevant.
What are the two sorts of error Giambattista Vico says can be made in thinking about the past? Can you identify times when you have made these errors? Do you find that you tend to make one kind rather than the other, or that you make one kind in some areas of your life and the other in other areas?
The social historian Giambattista Vico (1668-1744) observed that there are two common mistakes made when viewing the past. The first is to look back to a golden age, populated by individuals of incomparable intellectual and moral genius. The second sort of mistake is to view people of the past as ignorant and primitive, having nothing to teach the present.
Young children often make the first sort of error when they regard their parents as the source of all wisdom and truth. Adolescents are prone to the second kind of error when they assume that their parents are hopelessly ignorant and out of touch.
Write a short essay (300-500 words) linking the sense of wonder as a motive for science, the search for understanding and the goal of generality.
List the basic criteria for valid answers to scientific questions.]
- No answer can imply the violation of an established empirical fact, unless it also offers an explanation that shows why the cases in which this violation will occur are ones that have as yet not been observed. In this case, it offers predictions that can be tested.
- Every answer must either be consistent with existing theories, or provide a good reason for changing these theories.
- No answer can involve a logical contradiction.
Describe the 8 stages in the development of a scientific idea, or an entire field of science.
- Initial Interest: Every line of research in science begins when some phenomenon attracts somebody’s attention. Something unusual happens, or somebody thinks about something in a new way and thinks, “That’s funny, what’s going on here?” The object or event of interest is roughly described along with its more obvious properties and peculiarities.
- Delineation of the Phenomenon: By familiarizing themselves with the objects and events of interest, researchers begin to build a more comprehensive description of the phenomenon, and to develop an empathetic “feel” for the subject. On this basis, they choose or develop appropriate tools for a more in-depth study.
- Empirical Database: Through carefully designed observations and experiments targeting specific aspects of the phenomenon, researchers develop an empirical database.
- Classification and Conceptualization: Regularities in the empirical data are grouped into classes, and concepts are developed to characterize these classes. A taxonomy or typology may be constructed as a conceptual net to capture patterns appearing in the data. This is the stage where Plato’s injunction holds, “First the survey of scattered particulars, leading to their comprehension in one idea [then dividing the idea into parts] where the joint is, not breaking any part as a bad carver might.”[59]
- Generalization and Theory Construction: Relationships between the conceptual entities that have been defined are studied. Causal regularities are discovered and/or posited, and are either incorporated into existing theory or used as a basis for new theory.
- Hypothesis Generation and Testing: Hypotheses are put forward and used to generate new predictions that are tested in newly devised experiments or observational situations. In general different research groups may produce a variety of hypotheses but empirical tests alone may be insufficient to definitively eliminate all but one of the hypotheses.
- Analysis and Debate: There is a general discussion within the concerned scientific community, comparing the merits and demerits of hypotheses that have not been eliminated by empirical tests. Modifications of various hypotheses are proposed and tested as the scientific community works toward consensus.
- Assimilation into Existing Theory: At some point, the preponderance of evidence will lead to the acceptance of a hypothesis or theoretical construct as most likely, or if no definitive empirical selection emerges, as most elegant. That hypothesis is then assimilated as a part of the existing theoretical structure of the science, and is incorporated into undergraduate textbooks.
When we compare this formulation to the four stages described by Omnès, we see that his Exploration Stage involves our Stages 1, 2 and 3; his Conceptual Stage is our Stage 4; his Developmental Stage is our Stage 5; and his Verification Stage covers our Stages 6, 7 and 8.
When presented in this form, the process described seems linear, moving from initial interest to accepted theory. This impression is just an artifact of the form of presentation. In the actual practice of science, work is going on in each of these eight stages simultaneously, although one stage may receive more attention and effort at any given time. In addition, there are feedback and feedforward links among stages, and the overall process itself is cyclic—the accepted theory that appears at Stage 8 is also part of the background against which new phenomena of interest will emerge.
The discussions and debates going on in Stage 7 are carried out within the context of this background of accepted theory, and they are the source of many of the new questions and new phenomena that initially excite scientific interest in Stage 1. Likewise, the move from Stage 1 to Stage 2 requires consideration of Stage 4, since the tools developed, and the way that the data are to be worked over in Stage 2, both require consideration of the sort of conceptual structures that are available for representation. If we want a taxonomy that carves nature with a scalpel we don’t want to carry out our experiments using equipment that carves with an axe.
The accumulation of empirical data moves the process from Stage 2 to Stage 4, but it also requires us to think in terms of the currently accepted theories (Stage 8). That is, the way that we develop concepts and classify entities in Stage 4 is determined by the condition that it be possible eventually to incorporate these concepts into existing theory, or at least to show how they are consistent with this theory. If it appears impossible to do so, then we will need to consider changes to the existing theory. In either case, the work at Stage 4 is carried out in a conceptual framework in which current theory provides the paradigm. The work of harmonizing the new work with existing theory is carried out in Stage 5, and will automatically lead to the generation of new hypotheses to be tested in Stage 6. Again, this process is automatically followed by the discussions and debates of Stage 7, which prepare the new work for general acceptance, and also initiate a new cycle of activity by raising new questions of interest.
What are the four characteristics of a good question?
- It has depth—it goes to the heart of a situation.
- It is tantalizing—it seems to hold out the possibility of an answer.
- It is suggestive—it almost tells one how to look for an answer.
- It is fruitful—the answer, when obtained, will have significant meaning for several areas of science
Write a short essay (300-500 words) comparing the criteria for a valid answer in science to criteria for a valid answer in some other area of human activity such as law, literature, art or religion.
Science
- No answer can imply the violation of an established empirical fact, unless it also offers an explanation that shows why the cases in which this violation will occur are ones that have as yet not been observed. In this case, it offers predictions that can be tested.
- Every answer must either be consistent with existing theories, or provide a good reason for changing these theories.
- No answer can involve a logical contradiction.
Identify at least five sorts of questions that can be asked in science.
- We may ask whether or not a particular hypothesis is
a. “true.”
b. consistent with a given theory.
c. consistent with experiment.
- Assuming that a given theory or hypothesis is “true,” we ask what consequences its truth implies
a. for further theory development.
b. for possible predictions that can be made.
3. We may ask what must be assumed as true in order for a particular result to follow; for example, asking what must be assumed to explain the motion of the planets.
- We may ask about the nature of the relation between elements of some set or collection. Linnaeus, for example, asked about the relations between different kinds of plants and animals, and answered in terms of a species concept based on the possibility of interbreeding: plants or animals of the same species could mate and produce fertile offspring, those of different species could not.
- We may ask about the composition or structure of some entity. For example, Dalton asked how chemical compounds might be composed, and developed the atomic theory of matter.
- We may ask why a thing is a particular way, and not otherwise. For example, the astronomer Wilhelm Olbers (1758-1840) asked the question: Why is the night sky dark? The query was proposed as a paradox: if an infinite number of stars exist, then any line of sight should eventually encounter a star, and the entire sky should be bright. Why is this not so?
- We may ask what data must be obtained, and how one might go about obtaining it, to test a particular hypothesis or theory. For example, in 1919 an expedition to Paraguay was undertaken to measure the bending of starlight by the sun, an effect predicted by Einstein’s general theory of relativity
Describe Roland Omnès’s four stages of scientific activity as presented in Discussion 3.2.
- Exploratory Stage: This initial stage “consists in the observation of facts, the performing of experiments ‘to see what happens,’ the compiling of a catalogue of data, and, eventually, the discovery of empirical rules.”
- Conceptual Stage: This stage “consists in the development and the selection of appropriate concepts permitting a representation of Reality, the invention of the principle, or principles, that might govern this representation.”
- Developmental Stage: This stage “consists in examining all possible consequences of the principles. . . . In most cases, only certain consequences are considered, primarily those concerning known facts.”
- Verification Stage: In this stage, “each prediction is systematically subjected to the test of experience.” Successful predictions lead to tentative acceptance, unsuccessful ones mean that the theory is false, or at least incomplete, and that further clarification is required.
Describe three different ways that scientific discoveries have been made, and give an example of each.
Mendeleev’s creation of the periodic table of elements. Wegener’s theory of continental drift and the discovery of plate tectonics. (looking for patterns as a key to discovery)
The discovery of superconductivity, or the loss of electrical resistance in certain metals at a critically low temperature, made possible by cryogenics. Leeuwenhoek’s discovery of microbes, made possible by his improved microscopes. The discovery of quasars, made possible by radio astronomy. (expanding our world with instrumentation)
The discovery of argon and the inert gases resulting from a discrepancy in the measured density of atmospheric nitrogen. The discovery of atmospheric pressure and the invention of the barometer due to the fact that suction pumps could only pump water 34 feet high. The discovery of Neptune due to a discrepancy between the observed and predicted orbits of Uranus. (discrepancies as a trigger to discovery)
What were the major pieces of evidence that led Snow to his discovery of how cholera is transmitted?
The question of how cholera spread was complicated: evidence indicated that it could be transmitted by close personal contact, yet some people (especially physicians) who had close contact with cholera victims did not get the disease. In addition, the disease could appear far away from existing outbreaks. A number of people, both physicians and others, blamed the water supply. Snow adopted this theory, refining it by specifically implicating the excretions of victims. He was able to provide convincing empirical proof in support of this theory. He did this by recognizing that in a particular district of London where an outbreak had occurred, some houses got their water from one water company and other houses got theirs from a different water company. Further, that these two companies drew their water from different parts of the River Thames.
He then made two strong arguments against the effluvia theory: (1) even though everybody who is in close contact with a victim of the disease will breathe in the effluvia, not everybody in such contact gets sick; and (2) in some cases, cholera breaks out in new areas where nobody has been exposed to previous victims.
In addition, there was substantial evidence that contamination could be spread through the water supply. During the 1853-1854 outbreak in Soho, Snow noticed that many victims came from households that obtained their water from a pump on Broad Street. He convinced the parish Board of Guardians to remove the pump handle, and the incidence of cholera in the area dropped significantly. Further evidence supported the idea that contaminated water from this pump had been a source of the spread of cholera: two groups living near the Broad street pump had very few cases. These were the inhabitants of a workhouse and the employees of a brewery, neither of whom drank from the pump.
Another line of Snow’s argument involved analysis of death rates between customers of the Lambeth Waterworks Company (which had moved its water intake upstream to a place not contaminated by London sewage) and the Southwark and Vauxhall Water Company (which drew its water from contaminated regions of the river).
Identify the main questions that Snow asked, and describe how he answered them as he carried out his research.
Chapter 5 of What Science Is describes the history of our theories of planetary motion. Apply the eight-stage model of scientific development given in Discussion 3.2 to map out the corresponding stages in this history. Note that you may need to consider more than a single cycle of this process.
Describe some case histories of scientific discovery in terms of the question-and-answer process.
