Tansu KUCUKONCU , PhD
( Tansu KÜÇÜKÖNCÜ ( in Turkish alphabet ) )
Pierre Maurice Marie DUHEM
Survey by Tansu KUCUKONCU
He is a French physicist and philosopher who lived between 1861 and 1916.
His basic thoughts are listed below:
* One could not fully understand a scientific theory or concept without
knowledge of its origins and the development of the problems which it was
designed to solve.
* One of his principal aims is to make a clear theoretical seperation
between physics and metaphysics.
The mataphysician is concerned with explanation, to explain being, 'to
strip reality of appearences covering it like a veil, in order to see the
bare reality itself'. But it's only metaphysics which raises the question
whether there is reality underlying or distinct from sensible appearences.
A physical theory is not an explanation. It is a system of mathematical
propositions, deduced from a small number of principles, which aim at
representing as simply, as completely and as exactly as possible a set of
experimental laws.
* Mathematical deductions have no meaning for a physicist unless they
have physical equivalents.
* 'Agreement with experiments is the sole criterion of truth for a
physical theory'.
A physicist does not conduct physics without some sort of theory.
Physical theory has no objective validity independently of experiment.
* An experiment in physics is the precise observation of phenomena
accompanied by an interpretation of these phenomena; this interpretation
substitute for the concrete data really gathered by observation abstract and
symbolic representations which corresponds to them by virtue of the theories
admitted by the observer.
* It would be unreasonable to work for the progress of physical theory
if this theory were not the increasingly better defined and more precise
reflection of a metaphysics; the belief in an order transcending physics is
the sole justification of physical theory.
* A physical theory does not explain the laws, though it coordinates
them systematically. Nor do the laws explain reality; what we know are the
relations between sensible phonomena.
* Every physical theory is an approximate law. Consequently it can not be,
for the strict logician, either true or false; any other law representing
the same experiments with the same approximation may lay as just a claim as
the first to the title of a true law or, to speak more precisely, of an
acceptable law.
* The more perfect the methods of measurements are, the closer is the
approximation and the narrower the limits. But they never become so narrow
that they vanish.
* He argues that the falsification of a theory is necessarily ambigious
and therefore that there is not and cannot be a 'crucial experiment' in F.
Bacon's sense of phrase. For which the physicist can never be sure that there
is not another conceivable hypothesis which would cover the phenomena in
question. (one can never be sure that it is a given theory rather than
auxilary or background hypothesis which experiment has falsified)
But as the number of rescue operations increases, the theory may lost
its simplicity, so it may be more appropriate to chance it with a new one.
* He refuse to admit that there are scientific hypoteses which are beyond
the reach of experimental refutation and must be regarded as definitions
which remain unaffected by emprical testing.
* In an experiment the formula which was useless when we employed one
of the equipments (tools) may become useful when we employ the second.
* He adds indeed that we cannot avoid the feeling that observed relations
correspond to something in things apart from their sensible appearences to
us. But he insists that this is a matter of natural faith or belief and not
something which can be proved in physics.
* Scientific theories permit predictions. Some of this predictions are
emprically testable. If they are verified, the value of the theory is
increased. If a prediction which represents a legitimate conclusion from a
theory is falsified, then that theory must be modified (if not abondened).
If we assume the truth of a given hypothesis and then deduce that on this
assumption a certain event should occur in certain circumstances, the accual
occurance of the event in these circumstances does not prove the truth of the
hypothesis.
* Science advences through the elimination of hypothesis rather than
through verification in a strong sense.
* Science makes progress because experiments constantly causes new
disagreements to break out between laws and facts, and because physicist
constantly touch up and modify laws in order that they may more faithfully
represent facts.
* We can foolow the slow and graduated transformations through which the
theoretical system evolved; but at no time can we see a sudden and arbitrary
creation of new hypotesis.
* His interpretation of physics is 'positivist in its conclusions as well
as in its origins. He rejects metaphysics
* Experimental approaches do not have the power to transform a physical
hypotesis into an indisputable truth; in order to confer this power on it,
it would be necessary to enumerate completely the various hypothesis which
may cover a determinate group phenomena; but the physicist is never sure he
has exhausted all the imaginable assumptions.
