|Experiment: artificial bringing about of an event or artificial creation of a state for testing a hypothesis. Experiments can lead to the reformulation of the initial hypotheses and the reformulation of theories. See also theories, measuring, science, hypotheses, Bayesianism, confirmation, events, paradigm change, reference systems._____________Annotation: The above characterizations of concepts are neither definitions nor exhausting presentations of problems related to them. Instead, they are intended to give a short introduction to the contributions below. – Lexicon of Arguments. |
Pierre Duhem on Experiments - Dictionary of Arguments
Experiment/Duhem: The experimenter does not merely read the instruments, he uses the instruments. The following are required:
1.Theory about the domain in which measurements are made.
2.Theory of used measuring instruments. In every device there are systematic errors, the experimenter knows that. Duhem: the Ex works constantly with two devices: the concrete measuring device and an ideal structure for which the physical laws "exactly" apply.
Between the phenomena ascertained in the experiment and the result of the experiment formulated by the physicist is a complex translation process. The facts which the experimenter determines are already "theoretical facts". The experimenter must always use theories for his work. The results are only useful for other physicists, if it is know which theories he has used. And whether corrections were already made.
An experimentum crucis (whose failure would disprove the whole theory) is rejected. (> Holism).
VsExperimentum crucis: (for example, by Quine, 1951, as the main attack against logical empiricism: Holistic view of science.) No experiment can show where the fault is located in the system. The examination of a particular hypothesis is only possible by using a whole group of further laws, ultimately the whole theory.
Since Bacon, hope was linked to an experimentum crucis: a decision-making experiment between competing theories.
E.g. Foucault's attempt to decide between Newton's theory of emission of light and Huygens' undulation theory sees Duhem as an experiment of the experimentum crucis. Foucault was able to show that light actually spreads slower in water, which made Newton look refuted. Duhem shows that this conclusion is not valid. The error could be in a secondary hypothesis.
Experiment/Duhem: disintegrates into two parts.
1. Observation of certain facts. For this, the knowledge of physics is not necessary at all.
2. Interpretation of the observed facts. For this you have to know the physics. The physicist does not write in his protocol that the instrument has indicated a certain stroke, he notes that the gas has reached a certain volume.
What are the size of the volume, the temperature, the pressure? Three concrete objects? No, there are three abstract symbols that connect physical theory with facts.
Definition experiment: accurate observation of a group of phenomena, plus interpretation of them.
This interpretation replaces the concrete given with the help of the observation of actual ones obtained by abstract and symbolic representations which agree with them on the basis of the theories which the observer accepts as permissible.
Experiment: The result is the establishment of a relationship between different concrete facts.
A certain fact was artificially produced, another stems from it.
Experiment/Duhem: We must know the theories that the physicist considers valid.
During the experiment, the physicist continued to operate two apparatuses side by side: the actual measuring apparatus and the ideal one defined by mathematical formulas and symbols.
The result of a physical experiment has not a security of the same level as a fact, established by non-scientific methods, from a healthy person by simple observation. The experiment is less direct and more dependent on a whole group of theories.
Experiment/Duhem: The experiment is not the basis of theory, but the highlight. The totality of the theorems gives an ever more similar picture of the totality of the experimental facts._____________Explanation of symbols: Roman numerals indicate the source, arabic numerals indicate the page number. The corresponding books are indicated on the right hand side. ((s)…): Comment by the sender of the contribution. Translations: Dictionary of Arguments The note [Author1]Vs[Author2] or [Author]Vs[term] is an addition from the Dictionary of Arguments. If a German edition is specified, the page numbers refer to this edition.
La théorie physique, son objet et sa structure, Paris 1906
Ziel und Struktur der physikalischen Theorien Hamburg 1998