Gsx, just a bit more clarification on what a theory, a law and a fact is, in scientific terminology.
A law is a general statement about how things are observed to behave.
Thus, Newton's law of gravity is formulated thus: F = GmM/r^2 . I.e., the gravitational force between two objects of masses m and M is equal to the product of the masses, times a proportionality constant called "G" (the universal gravitational constant), divided by the square of the distance between the centers of the masses.
A statement about how things apparently behave becomes a law when sufficient time has passed and sufficient observations have been made that scientists are extremely confident that no exceptions will be found. That does not mean that a law is absolute -- it only means that scientists are confident that it is a correct statement about the world.
A theory is a set of statements about how things behave plus, more importantly, why things behave as they are observed to. Thus the theory of gravitation proposed by Einstein incorporates Newton's law of gravity plus a lot of other potential laws, plus a lot of statements about why gravity behaves the way it does, plus predictions about what new observations might show.
A fact is a statement that has general and wide acceptance. A difference between a fact and a law is that a law is usually a formal statement about how a specific thing behaves, whereas a fact is much broader. We have Newton's law of gravity as narrowly defined above, and we have the broad fact of evolution. "The fact of evolution" means that a great deal of evidence indicates that life on earth has undergone great changes over millions of years, changes that form a sequence that look exactly like "descent with modification".
The late Stephen Gould gave an excellent description of these ideas:
In the American vernacular, theory often meansimperfect fact part of a hierarchy of confidencerunning downhill from fact to theory to hypothesis toguess. Thus the power of the creationist argument:evolution is only a theory and intense debate nowrages about many aspects of the theory. If evolutionis worse than a fact, and scientists cant even makeup their minds about the theory, then what confidencecan we have in it? Indeed, President Reagan echoedthis argument before an evangelical group in Dallaswhen he said (in what I devoutly hope was campaignrhetoric): Well it is a theory. It is a scientific theory only, and it has in recent years beenchallenged in the world of science that is, notbelieved in the scientific community to be asinfallible as it once was.
Well, evolution is a theory. It is also a fact. Andfacts and theories are different things, not rungs ina hierarchy of increasing certainty. Facts are theworlds data. Theories are structures of ideas thatexplain and interpret facts. Facts dont go away whenscientists debate rival theories to explain them.Einsteins theory of gravitation replaced Newtons inthis century, but apples didnt suspend themselves inmidair, pending the outcome. And humans evolved fromape-like ancestors whether they did so by Darwinsproposed mechanism or by some other yet to bediscovered.
Moreover, fact doesnt mean absolute certainty;there aint no such animal in an exciting and complexworld. The final proofs of logic and mathematics flowdeductively from stated premises and achieve certaintyonly because they are not about the empirical world.Evolutionists make no claim for perpetual truth,though creationists often do (and then attack us for astyle of argument that they themselves favor). Inscience, fact can only mean confirmed to such adegree that it would be perverse to withholdprovisional assent. I suppose that apples mightstart to rise tomorrow, but the possibility does notmerit equal time in physics classrooms.
AlanF
5 July 2002 11:56:41
Edited by - AlanF on 5 July 2002 11:57:38
Edited by - AlanF on 5 July 2002 11:59:6
