How Science Progresses -- By Overturning Old Paradigms?

There is a common view of how science progresses, that it progresses by continually overturning old paradigms. Advocates of various forms of crackpottery are, not surprisingly, especially fond of this view; they often seems to think that all it takes to accept their views is a paradigm shift.But what has really happened?In many cases, new paradigms subsume or include old paradigms as special cases or consequences or something else that does not imply falsification. Here are some case studies.Newtonian mechanics was a big jump over what had gone on previously; it is fair to call it a paradigm shift. Its successors, relativity and quantum mechanics, have enough differences from Newtonianism to be called paradigm shifts. But they also have many close resemblances to Newtonianism, and they include Newtonian mechanics as a limiting case. So Newtonianism was only falsified in some very strict sense; it was shown to be an approximation that has some well-defined amount of error.In chemistry, the modern concept of chemical elements emerged in the 18th century; it was a drastic departure from the ancient conception of elements as earth, air, fire, and water -- those "elements" correspond more closely to states of matter. So it may justly be called a paradigm shift. Lavoisier's mid-18th-cy. list of elements has held up very well, with most of them being either presently-recognized elements or oxides of them. Later developments, even those worthy of being called paradigm shifts, only built on this conception. These includeThe Law of Definite Proportions
Atomic Theory
Valence Theory
The Periodic Table of Elementsand the 20th-cy. demonstration that atoms are really composite entities whose parts follow laws of physics.Each advance included without falsifying what went before, so paradigm replacement simply did not happen.Turning to geology, the development of radioisotope dating dramatically confirmed the relative order of the geologic column that had been worked out over the century before; igneous rocks have the "right" order of crystallization ages.And in biology, Mendelian genetics is a successful paradigm that was dramatically confirmed by the working out of molecular-genetics paradigms, notably the discovery of the structure and workings of nucleic acids (DNA and RNA).There are several other examples I could give; suffice it to say that perpetual overturning simply does not happen.I now turn to the paradigm of evolution by natural selection, which was first proposed by Charles Darwin in his Origin of Species. He justly deserves to be called a founder figure, because he had developed his concepts in considerable detail, addressing numerous objections. And his work has held up remarkably well, with his main errors being:Heredity: modern biology out-Darwins Darwin, rejecting the heritability of "the effects of use and disuse".Gradualism: modern biology also accommodates the much-observed lack of fossil gradualism -- evolution often works in bursts ("punctuated equilibrium").In fact, molecular biology offers remarkable confirmations of family trees developed earlier -- human genes have much more sequence similarity with corresponding chimp genes than with dog genes or snake genes or frog genes or fish genes or fly genes or yeast genes or sunflower genes or bacterium genes.So looking to the overthrow of evolution is a lost cause -- anything that "overthrows" it would have to somehow account for the appearance of evolution.

That's right -- it's Thomas Kuhn's theory, expounded in his book The Structure of Scientific Revolutions.

There are more appropriate places to debate Flood Geology in this bboard; however, tranquility base's scenario reminds me of what has occasionally happened in cutting-edge research. In the 1920's, physicists Erwin Schroedinger and Werner Heisenberg developed rigorous formulations of quantum mechanics that were very different-looking. In Heisenberg's formulation, the wavefunctions are fixed and the operators (observable quantities, etc.) are dynamic. While in Schroedinger's formulation, the wavefunctions are dynamic and the operators fixed. However, it turned out that Heisenberg's and Schroedinger's formulations were mathematically equivalent!More generally, in cutting-edge research, scientists often propose and advocate several competing theories, with advocates of rival theories sometimes using rather flamey rhetoric on each other. But such controversies usually end up being resolved in some way or other; the poor performers are discarded, and the "winners" are often reconciled, like being shown to be different special cases.I think that one good indicator of immature science is the lack of resolution of such controversies; the social sciences often seem to be in such an immature state. Also, the progress of science may run out of steam in some cases, from a lack of good data to distinguish hypotheses.That has actually happened in evolutionary biology -- the grouping of the eutherian (placental-mammal) orders has long been a subject of controversy, because of the difficulty of identifying features that could be indicative of such groups.But in recent years, molecular-phylogeny techniques have improved enough to make it possible to resolve that question, with some startling results. For example, elephants, sirenians, hyraxes, aardvarks, golden moles, elephant shrews, and tenrecs are recognizably united in the taxon Afrotheria -- which has essentially no macroscopic-feature support. There is some for the grouping Paenungulata of elephants, sirenians, and hyraxes, and that grouping is indeed confirmed by the molecular evidence, but that's about it.

Tranquility Base:
(to Joe Meert) ... In the future I will make a point of stating that mainstream geology accepts catastrophism where necessary. Actually, it is not a choice between grandiose all-encompassing philosophies; gradualism and catastrophism are supported to the extent that they fit the data.Although Lyell may well have performed a rhetorical snow job, early 19th-cy. uniformitarianism was in better shape conceptually than early 19th-cy. catastrophism. That's because catastrophism back then was not much more than the satirical cartoon about some scientists and a complicated derivation on a blackboard which had this in the middle:... and then a miracle happens ...Catastrophism has made a comeback over the last half-century because catastrophes could be much better understood. I'll discuss some examples:The Earth is known to have ~160 impact craters; many of these have been identified by looking for something that can only be produced by the impact of a fast, massive object: "shock metamorphism" in nearby rocks. An identification made possible by asking: what would a big rock hitting the Earth at 30 km/s do that nothing else would do?Without that important clue, there would be little to indicate that many craters were really craters, since they are often highly eroded.There is evidence of giant glacial-dam-break floods during the Pleistocene, notably in the US Pacific Northwest Columbia River Basin and in the Altai Mountains. J Harlen Bretz had studied the Columbia River Basin's landforms back in the 1920's and had found them to have lots of features typical of flowing water -- but flowing water at a scale much larger than even the biggest river. Other geologists were totally skeptical; floods that size simply do not happen. Or at least have not happened in front of anyone who could have recorded their occurrence.But when other geologists went out to the Columbia River Basin, they saw what JHB had seen, and they realized that he was right about there having been huge floods there. And they even identified the source: a former lake near Missoula, Montana. It was dammed by a lobe of the North America's Pleistocene ice sheet, but every so often, that lobe would break and the water of Lake Missoula would rush out to the sea. Something similar, often called jokulhlaups, happens in icy mountainous regions, though on a smaller scale.However, I made it clear in my introduciton that my purpose was to show that both mechanisms somewhat coincidentally explain the same data.Another forum here would be a better place, but it's clear why Flood Geology was rejected -- there are too many things that simply do not fit very well. And would-be rebuttals often make Noah's Flood into sort of magic flood that can produce any landform whatsoever. There is nothing like the shock metamorphism that clinches the case for big impacts or the large-scale flow features that clinch the case for those giant Pleistocene floods.You missed the point that Lyell et al used these three pieces of data as catch cries of gradualism when further research demonstrates them to be nothing of the sort. They are not points of distinguishment between the models.If that is the case, that would be an interesting conundrum. But if one model requires many more ad hoc hypotheses than another, then the one with the fewer such hypotheses will be preferred by everybody with any sense. And Flood Geology is clearly in the ad-hoc-heavy category.There is room for a huge paradigm shift in geology despite your limited acceptance of catastrophic mechanisms.Except that paradigm shifts do not happen because one wants them to. One has to present a superior model, and to overcome potential difficulties.Continental drift was accepted late in the history of geology for a simple reason: what could make continents plow through oceanic crust? The early "drifters" like Wegener and du Toit did not make things any better with their extremely implausible mechanisms.However, in the 1950's, evidence of seafloor spreading was discovered, and that led to the concept of "plate tectonics". Continents do not plow through oceanic crust; instead, they drift with that crust. And having gotten over that conceptual barrier, geologists soon discovered that continental drift provided solutions to numerous geological riddles. And precise-positioning experiments have enabled observations of continental drift -- observations which closely agree with the estimated drift over the last few million years.Can Flood Geology advocates point to anything similar?

Tranquility Base:
Yes but what is never actually commented on here by the eons-side is that almost every formaiton has a corresponding obvious rapid mechanism of generation.Is there some formation that doesn't?You simply pick the gradualism explanation and ignore the evidence of rapidity and catastrophe (systematic rapid and consistent current flow revealed by ripples, cross-bedding and ordered pebbles; incredibly high purity and large scale of strata and systematic presence of fossil graveyards).Rapid and consistent currents can be produced by rivers, especially flooding rivers.Furthermore, the fine scale of some formations points directly to slow rather than fast deposition.And fossil graveyards can easily be produced by gradualistic processes and by such "catastrophes" as flooding rivers.The formations of them were clearly separate events, as distinguished by their different fossil contents. One well-known one, the La Brea Tar Pits, had lots of animals and plants in it that were either of presently-living species or of closely-related extinct species. Which was certainly not the case for older fossil graveyards. So why this neat sorting?We both choose the interpretation we prefer but we admit our difficulties, your side rarely admits anything.TB, what difficulties have Flood Geologists explicitly admitted? Yes, I am dead serious about the explicit part.You give the layman the feeling that starta wer elaid down gradually. That is a ridiculous interpretaiton for around 50% of the geo-col.And how is that supposed to be the case?It is easy to study existing lakes and look for layers. It is not so easy to locate a recent catastrophic event and loko for layers or set it up experimentally.TB admits that the single-catastrophe hypothesis is counterindicated by lake-bottom layers.Me:
The Earth is known to have ~160 impact craters; ...Why are you all so sure we don't accept these events? We beleive that catastrophism was not limited to Earth. The marring that the moon (and Earth) received extraterrestially was also a catastrophic event realted to creaiton/flood in our view.However, many craters are heavily eroded, and some, like Chicxulub, have been buried by sediment.And my point in mentioning them is simple: how they were established to be impact craters.There is nothing like the shock metamorphism that clinches the case for big impacts or the large-scale flow features that clinch the case for those giant Pleistocene floods.We think you have huge blinkers on.Like what? There is absolutely zero evidence that the rocks starting with the Cambrian had been laid down by a single year-long planetwide flood.The paleocurrents, fossil graveyards, coal fields, sorting and vast scope do actually scream global flood!Only to someone who desperately wants to believe in Flood Geology. Coal is often found in "cyclothems", which are alternations of coal and rock -- often several in sequence.The only reason our scenario appears more ad hoc is that you ingensouly propose a new sub-environment type for every formation and claim it is not ad hoc! It's a just-so-story best fitted to the closest modern analogy. You can explain anything by such story telling (just as we can).Except that we don't have to fit everything into one year, complete with multiple episodes of consolidation, faulting, erosion, evaporation, lava flows, etc. In fact, we have an objective timescale: radioisotope-decay dating.I will not argue ours is better at this point. We have only spent about 100 serious man-years on this scenario compared to your millions of man-years.Cry us all a river as big as the Amazon. How much research effort will you Flood Geologists need before you realize that Flood Geology simply cannot work? And I don't think I want to see any more postmodern poppycock about how one geologist sees gradualism and how another sees Noah's Flood.(continental drift...)
We simply have no problem with your scenario! We believe in the entire continental drift scenario, ...Including the formation of pre-Pangaea supercontinents like Rodinia? And evidence of former mountain ranges (orogens) extending back for ~2 billion years or more?And the formation of all of the Hawaii-Emperor seamount chain in a few centuries or less?[This message has been edited by lpetrich, 02-03-2003]