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Author
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Topic: Stone circles
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Paul A. Nelson
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Member # 26
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posted 22. January 2003 11:57
The cover photograph of this week's Science depicts the striking stone circles found in polar and high alpine regions. In the companion article, "Self-Organization of Sorted Pattern Ground," Science 299 (17 Jan 2003):380-381, M.A. Kessler and B.T. Werner describe the physical mechanisms thought to construct these (and other) remarkable structures. This CNN article on the publication includes a nice photograph of the circles:
http://www.cnn.com/2003/TECH/science/01/20/arctic.designs.ap/index.html
Some have suggested that stone circles and other "false positive" phenomena provide telling counterexamples to Dembski's explanatory filter. Well, Bill has been my design-theoretic colleague for 12 years, and we spent a lot of time early on (notably, at Cambridge UK in the summer of 1992, with Steve Meyer), going over problem cases such as stone circles. Indeed, it was the very existence of such phenomena that led us to the need for a method or inferential procedure like the explanatory filter.
Here's a bit of history to support the point. In the spring of 1984, as a college senior studying the philosophy of science at the University of Pittsburgh, I wrangled an independent study semester with Nicholas Rescher, a senior member of both the philosophy and history and philosophy of science faculties at Pitt. My topic, which led to a 112 page thesis, was "The Possibility of Design."
What follows is an excerpt from that thesis:
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(from Chapter 1, "The Possibility of Design," a thesis submitted to the Department of Philosophy, University of Pittsburgh, April 1984)
In the summer of 1976, the Viking Lander I touched down on the surface of Mars. After coming to rest on the smooth volcanic plain Chryse Planitia, the lander's cameras were turned on, and it began transmitting pictures of the surrounding landscape. The cameras revealed a windblown surface with boulders and blocks of various kinds.
Now I will change the story a bit. Suppose that, in the photographic survey of the landscape, a circle of stones had been observed (see Figure 1). I have redrawn this from some of the mission photographs, altering the foreground to display a circle of stones.
We must imagine ourselves as scientists on the mission research team. What would have been our likely reaction to such an arrangement? I think the question which would fairly leap into our minds is "Who, or what, made that circle?" Such an arrangement could hardly have been our expectation; it displays symmetry and regularity; it stands out against the surrounding background; and it seems unlikely that the stones could have arranged themselves. (Many such circles have been found here on Earth; of these, doubtless the best known is Stonehenge. The sort of circle I have in mind, however, and have drawn in the figure, is closer in appearance to the recumbent stone circles of Scotland, such as the Loanhead of Daviot. A large number of these circles, which may have had some ritual significance, are known from Aberdeenshire and adjacent counties, in the region surrounding Aberdeen in northeastern Scotland [Burl 1981, 66].) The circle appears to be an artifact; it satisfies all the ordinary criteria used to judge whether an object (or pattern) is artificial in nature. The circle gives every hint of being the product of some intelligence.
This conclusion may seem quite strong, almost certain. But such a conclusion cannot yet be safely drawn, because intelligent, purposive action is not the only cause of stone circles:
quote:
An interesting effect of ice-crystal growth in soils...is the moving of larger fragments of rock upward toward the surface and laterally to form rows. These fragments are in the size range of pebbles, cobbles, or small boulders. Where a rock fragment lies close to the surface, soil heat is conducted more rapidly to the surface, causing the growth of ice under the rock. Continued thickening of the ice layer heaves the rock fragment upward, causing it to rise to the surface, or even to be lifted above the surrounding ground surface. In arctic environments, particularly in the tundra climates, the larger fragments tend to be moved sideways as well as upward by such frost action and to be sorted out into narrow bands. The bands intersect to from a netlike pattern consisting of stone polygons. [Strahler 1981, 369] (See Figure 2.)
On the grounds of this knowledge alone, namely, that circles of stones may sometimes be the product of purposive intelligence, but may also be the product of mechanical weathering processes (frost action), what are we to conclude? What sorts of questions would be reasonable -- or unreasonable -- to ask about the Martian circle?
Suppose we are asked by some eager reporters, "Did Martians make the circle of stones?" I think the answer would have to be (no doubt disappointing them), "We don't know yet." It would, however, be quite incongruous to reply that Martians or some other hypothetical extraterrestrial intelligence couldn't have assembled the circle, because "that would imply design or purpose, and we all know that the only objects in the universe that are truly designed are here on Earth -- they are our artifacts." Such a statement can only be taken to mean that one could somehow know the results of an empirical inquiry even before the inquiry had begun; an inquiry, furthermore, of much uncertainty.
Just as incongruous would be the reply, "We can never know or even reasonably conclude that the circle of stones was made by an intelligence, because we must always consider natural explanations first, there is no shortage of such hypotheses, and another possibility could always be imagined."
But the most odd response would be along the lines of the following: "Design is simply unscientific. The appearance of intention and purpose, which many have perceived in the circle, is an illusion, and we will not entertain any such speculations, for we already know that they are unscientific." What a howl of indignation this answer would bring from the press corps, not to mention our scientific or philosophical colleagues!
What we have as imaginary planetary scientists is something which stands out against a background, an arrangement of great interest, which it would be inexplicable to ignore -- but to explain its origin, we must turn to our knowledge, such as it is, of any processes which could have formed such a structure. Because of the remarkable symmetry and regularity of the circle, relative to the disorganized background, and, perhaps, because of our strong desire to find evidence for other intelligences, the hypothesis of purposive action leaps forward as a candidate explanation.
But it would be very easy to make a mistake at this point, that is, to move down the wrong avenue of inquiry. Suppose we rushed to the conclusion that the circle had been assembled by Martians. As scientists we might very well waste our time and money in mounting a manned exploration to Mars, or a similar endeavor on that scale, only to find that the circle was quite natural; interesting, nonetheless, but not worth the effort and expense. Suppose, on the other hand, that we hastily concluded that the circle was nothing but a geological anomaly, on the grounds of the thoroughly obscure argument that an inference to design is always unscientific. We might then forsake the best evidence yet of some form of extraterrestrial intelligence.
This thought experiment establishes that design is an empirical possibility. Circles of stones occur on Earth both as natural and artificial phenomena; such circles could occur on Mars or elsewhere; it might very well be problematical whether the Martian circle was natural or artificial. I cannot see that this bit of speculation has come to any contradictory conclusions, or that "language has gone on a holiday."
[References
Burl, A. 1981. The Recumbent Stone Circles of Scotland. Scientific American 245, p. 66.
Strahler, Arthur. 1981. Physical Geology. New York: Harper & Row.]
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[ 22. January 2003, 12:13: Message edited by: Paul A. Nelson ]
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andyg
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posted 22. January 2003 12:38
Paul,
I'm not quite sure what point you're making here - if you put the stone circles thorugh Bill's filter, what answer do you get?
Andy
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Paul A. Nelson
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posted 22. January 2003 13:27
Andy,
I'm just making an historical observation, about the development of the explanatory filter as a rational reconstruction of design inferences. Some commentators offer patterns like naturally-occurring stone circles as challenges to the explanatory filter, as if Dembski (or other design theorists) had never considered such patterns as possible counterexamples. That's naive.
It's hard to use stone circles (i.e., sorted pattern grounds) now as a test of the filter, for obvious reasons. That's why I continue to talk up a carefully designed (no pun intended ![[Wink]](wink.gif) ) bit-string analysis experiment, where a large collection of bit strings is coded (intelligently vs. naturally-caused), the key is held securely, and the strings are then made available for all comers to sort. More about this later --
[ 22. January 2003, 13:58: Message edited by: Paul A. Nelson ]
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andyg
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posted 22. January 2003 13:50
Paul,
I don't have any of Bill's books to hand at the moment, so I don't know how he has dealt with this criticism of his filter.
I was interested to know a) what the filter tells you when you put stone circles through it "naively" - i.e. just taking them at face value without any of the additional information we have today, and b) how the additional information affects the process of the filter in this case.
Some people have argued that the filter should include another category, along the lines of "insufficient information at present" or simply "we don't know". Thoughts?
AndyG
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Frances
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posted 22. January 2003 13:55
Paul,
What would the outcome of Bill's filter have been lets say if it had been applied in last century? Others have raised the fairy circles as an example of a false positive. I would argue that before we knew what really caused them, the design inference would likely have assigned them to be intelligently designed. In fact, the name fairy circles, suggests as much.
Thus, it seems clear to me that the reliability of the filter depends strongly on our present understanding of science and as such may be highly vulnerable to false positives.
I would also be interesting in some references to stone circles as used against Dembski's claims. But in the end the issue of the stone circles has not gone away, it may be designed, it may be natural. As such stone circles may present an excellent example of false positives. Or as Andy has pointed out, we may need an additional choice such as 'we don't know' as suggested by Wilkins and Elsberry?
Del Ratschz presents another excellent example of a false positive in his critical evaluation of Dembski's design inference in Appendix A of his book "nature design and science: The status of design in natural science".
Tumbleweeds: A false positive p. 166
The story goes that Del was traveling with his family and saw a small tumbleweed cross the road in front of the car and rolled up to the fence and continued precisely through a small previously undetected hole in the fence.
[ 22. January 2003, 14:01: Message edited by: Frances ]
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Rex Kerr
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posted 22. January 2003 16:39
Paul, I'm afraid that the stone circle analysis is much more analagous to analysis of biological systems than the bit string analysis is. With stone circles, in the absence of knowledge of a mechanism, you have to deal with all of the real-world problems of noisy data, incomplete scientific knowledge, choice of method of modeling the data, and so on.
If you prefer using bit strings, does this mean that the filter is not yet ready for use in the real world? If we encode the stone patterns as a binary raster image and give you the corresponding bit string, will that help?
It seems to me that the key is that in order to use the filter, we must have a good assessment of the extent of our scientific knowledge. Specifically, we must be able to answer the question, how confident can we be that we can make an accurate estimate of the probability of this event using our current scientific knowledge? This, I think, is what would have ended up saving the stone circles from becoming a false positive in the past. Namely, when it came time to evaluate whether the circles were low probability, the answer would be, "We don't know, we haven't studied it enough." And the filter would stop there, with uncertainty.
Unfortunately, if this is what is needed to save stone circles from becoming false positives, I am afraid that essentially all biological processes will end up in the "don't know" state. The gaps in our knowledge of protein folding, development and differentiation, behavior and nervous system function, etc. etc. etc., are immense.
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andyg
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posted 22. January 2003 17:13
Rex wrote:
quote:
It seems to me that the key is that in order to use the filter, we must have a good assessment of the extent of our scientific knowledge. Specifically, we must be able to answer the question, how confident can we be that we can make an accurate estimate of the probability of this event using our current scientific knowledge? This, I think, is what would have ended up saving the stone circles from becoming a false positive in the past. Namely, when it came time to evaluate whether the circles were low probability, the answer would be, "We don't know, we haven't studied it enough." And the filter would stop there, with uncertainty.
In their article in Biology and Philosophy (Vol 16, pp711-724), Wilkins and Elsberry address this issue quite nicely:
quote:
The point is that Dembski's filer is supposed to regulate rational explanation, especially in science, and yet it is highly sensitive to the current state of knowledge. One single difference of information can change the inference from design to regularity to chance. This goes to the claim that Dembski's explanatory filter reliably finds design. Reliability, Dembski tells us, is the property that once an event is found to have the property of "design", no further knowledge will cause the event to be considered to have the property of "regularity" or "chance". What the filter lacks that real-world design inferences already have is a "Don't know" decision. If we can say of a problem that it is currently intractable or there is insufficient information to give a regularity or chance explanation *now*, then the Filter tells us we must ascribe it to design if it is specifiable. But it can be specifiable without the knowledge required to rule out regularity or chance explnataions. This is clearly a god of the gaps stance, and it can have only one purpose: to block further investigation into these problems
This post is mostly quote, but I'd like to hear Paul's comments before procceding further.
AndyG
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Paul A. Nelson
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posted 22. January 2003 21:09
Andy, Frances, Rex,
I don't know how one would submit stone circles to the explanatory filter in what Andy calls a "naive" way -- which I take to mean something like, "Let's pretend we don't have a physical mechanism to explain these patterns." Nor can we reasonably answer the question Frances poses about how the filter would have worked in the 19th century. A critic would say the filter would fail; an advocate, that it would work. (That's why I propose a genuine test, where the outcome should be unambiguous; see below.) Now, if someone showed me a photograph of arctic stone circles, my first act would be to trot off to the geology library to see what had already been learned or hypothesized about these structures. Presumably, we'd want any real-world application of the filter to do likewise. Assess what is already understood about the sort of event, or pattern, one wishes to explain, in the light of current knowledge.
Might one mistakenly attribute a pattern to design, when a perfectly adequate natural cause exists? Of course. Such errors have happened in the past, and will happen again. But Dembski has never claimed otherwise. We never reach a state of scientific knowledge where false positives are impossible. Nevertheless, humans do infer design, and the great majority of these inferences are remarkably stable over time -- as stable and reliable, in fact, as the very best knowledge in science. That says to me that the worry about false positives should not rise any higher in one's consciousness than the ordinary caution one takes in making any inference.
The "don't know" node of the filter is already there implicitly. Usually, one is thrown into uncertainty by failing to find a specification. There's a nice example of this in an article in the 20 December 2002 issue of Science, where an archeological site in Agarak, Armenia, is being discussed. Armenian archeologists claim that a volcanic outcrop was sculpted by Early Bronze Age artisans -- but others are doubtful:
quote:
...the site has already begun to spark vigorous debate. Some experts doubt, for instance, whether the bas relief heads along the cliff were carved by human hand. "I would have some reservations about the anthropic character of many of these 'carvings,' says archeologist Pierre Lombard of Lumiere University in Lyon, France. Although impressed by the site and the Armenian team's work, Lombard, an expert on the ancient Middle East, suggests that the "animal heads" could possibly be an effect of erosion. Others, however, argue that weathering alone is unlikely to have produced such features.
(Richard Stone, "Armenia Uncovers a Bronze Age Treasure Trove," Science 298 [2002]:2319-2320.)
Now if animal heads with the precision of a Michelangelo carving had been found -- no doubt about their origin. The specification would be tight.
But mistakes are possible. If someone doesn't want ever to make a mistake, science is no place to hang out.
About the bit string experiment. What's attractive about this idea is its simplicity. Given agreed definitions of "naturally caused" and "intelligently caused," and a third-party science organization able to keep the bit string key absolutely secure for a set time period (say, one year), one could apply the explanatory filter, or the procedure Wesley Elsberry and Jeff Shallit are developing, or any other candidate method, to the collection of strings. May the best method win! And one wouldn't have to pretend not to know things (e.g., like the physical mechanism of patterned ground formation). Just take the strings and sort them, and then score methods for false positives and so on.
I'll be back to this thread on Monday, January 27. Gotta give some lectures in Florida.
[ 22. January 2003, 21:12: Message edited by: Paul A. Nelson ]
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yersinia
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posted 22. January 2003 22:27
I vote we run this aerial photograph through the Design Filter:
And look who lives in the area:
...a real-live "mousetrap".
PS: It was my impression that Dembski contended that his filter did not give false design positives.
PPS: And also that prospective cases of ID were to be classified as IDed unless the proposed natural explanation had sufficient "causal specificity".
[ 22. January 2003, 22:32: Message edited by: yersinia ]
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Cre8ionist
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posted 23. January 2003 08:21
Hi all,
There is a clear difference between the circles made by nature and those which would trigger a
design inference, perhaps I could illustrate the difference here.
Nature creates designs to be sure, soap bubbles, the circles made by throwing a stone into the water, tornadoes and those mentioned in this thread all qualify as natural designs. They trigger a "natural design" inference.
But as I mentioned in another thread they are lacking something which would keep them from
triggering an intelligent design inference.
Like Guy Berthault's sifting experiments, they prove that nature can pull matter into certain specified shapes and configurations, that rocks can be naturally separated from soil if you will. What they don't do is show that nature can originate CSI.
If, on the other hand you were to find a message written in the circles of sufficient length you would most certainly have a clear designsignature.
Again, if you put scrabble pieces down a drain you have the kind of structure which nature can produce, but if you arrange scrabble pieces on a board, into linked words, you have the kind which intelligence can produce.
Running the scrabble pieces which are in the vortex through the design filter would be akin to running the naturally occurring circles through, IMO..............................................Cre8
[ 23. January 2003, 08:26: Message edited by: Cre8ionist ]
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pz
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posted 23. January 2003 09:36
quote:
I don't know how one would submit stone circles to the explanatory filter in what Andy calls a "naive" way -- which I take to mean something like, "Let's pretend we don't have a physical mechanism to explain these patterns." Nor can we reasonably answer the question Frances poses about how the filter would have worked in the 19th century. A critic would say the filter would fail; an advocate, that it would work.
This is actually an interesting test case, and I don't understand why the specified complexity advocates aren't jumping all over it to demonstrate their method. It's a simpler system with fewer components and a less tortured history than a biological system, so it ought to be a cleaner exercise to just demonstrate how to use the filter.
You admit that you don't know how to apply the filter to this example in a naive way. I don't either. I don't see how to apply it in an informed way, either -- do you?
All I've seen here so far is admissions that people don't know how to apply the filter, that its results will depend on the state of knowledge, and that its results will also be subject to the bias of the person applying it. Isn't all that an admission that the filter simply doesn't work and doesn't even really exist?
[ 23. January 2003, 09:37: Message edited by: pz ]
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andyg
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posted 23. January 2003 12:44
Paul,
The point about the use of the filter in the stone circle case being considered from a "naive" or historical perspective is to make the point (as do Wilkins and Elsberry) that the filter is extremely sensitive to changes in knowledge. This makes me doubt its utility.
You also wrote:
quote:
Nevertheless, humans do infer design, and the great majority of these inferences are remarkably stable over time -- as stable and reliable, in fact, as the very best knowledge in science.
This is slightly misleading - humans only infer design reliably or stably to things that are, or appear to be, designed by humans. We tend to be rather bad at inferring design in other things. One egregious type of this behaviour is exhibited by certain creationists who use the argument:
1. Machines are designed.
2. Scientists such as Paul Boyer or Lucy Shapiro have referred to the F1-ATPase or bacterial flagellum as machines.
3. Therefore, these structures were designed.
I am sure neither Paul Nelson nor Bill Dembski would make this sort of error. But the point remains - we aren't very good at detecting non-human design. The cases of naturalists like Paley are another example that haven't really stood the test of time.
Rather than dredge up a Paley quote, I thought it might be amusing to quote a slightly earlier proponent of design in nature, William Bartram, from 1791, especially since he refers to an interesting predecessor of Behe's mousetrap........
quote:
"In every order of nature, we perceive a variety of qualities
distributed amongst individuals, designed for different purposes and
uses, yet it appears evident, that the great Author has impartially
distributed his favours to his creatures, so that the attributes of each
one seem to be of sufficient important to manifest the divine and
inimitable workmanship....
But admirable are the properties of the extraordinary Dionea
muscipula! [Venus flytrap] A great extent on each side of that
serpentine rivulet, is occupied by those sportive vegetables--let us
advance to the spot in which nature has seated them. Astonishing
production! see the incarnate lobes expanding, how gay and ludicrous
they appear! ready on the spring to intrap incautious deluded insects,
what artifice! there behold one of the leaves just closed upon a
struggling fly, another has got a worm, its hold is sure, its prey can
never escape--carniverous vegetable! Can we after viewing this object,
hesitate a moment to confess, that vegetable beings are endued with
some sensible faculties or attributes, similar to those that dignify
animal nature; they are organical, living and self-moving bodies, for we
see here, in this plant, motion and volition. ... "
When you return from your lectures, it would be nice to hear what *you* (not Bill) mean by "specification" in the sense of the phrase "specified complexity". In particular, could you explain to what degree the phrase "specified complexity" differs from "complexity that is unlikely to have arisen by chance"?
Moderator: Again, apologies for the short post. I hope this mode of "Socratic Brainstorming" is acceptable. I don't think there is much point in writing long pieces unless one is confident that we are all on the same page.
AndyG
[ 23. January 2003, 13:52: Message edited by: andyg ]
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Frances
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posted 23. January 2003 12:45
Paul
quote:
Might one mistakenly attribute a pattern to design, when a perfectly adequate natural cause exists? Of course. Such errors have happened in the past, and will happen again. But Dembski has never claimed otherwise. We never reach a state of scientific knowledge where false positives are impossible.
Your response confuses me since reading NFL left me with the impression that Bill argued that there were no false positives for the filter.
quote:
want, then, to argue that specified complexity is a reliable criterion for detecting design. Alternatively, I want to argue that the complexity-specification criterion successfully avoids false positives -- in other words, whenever it attributes design, it does so correctly.
-- WA Dembski, "No Free Lunch", p.24
Source
If his argument is that there are no false positives in a perfect world then his design inference is either an abstraction of reality and seems to fail to take into consideration such imperfect knowledge. False positives in an eliminative approach are quite serious since they undermine the practical application of it. Since we do not have direct evidence, how can we be sure that the findings of the design inference are not false positives? When can we make a reliable design inference and still take into account our imperfect knowledge?
I believe this is why Elsberry and Wilkins proposed a 'we don't know' branch, although you argue that we don;t know is covered by the filter through the specification but I would argue that specification is almost trivial and in fact as Sobel argues, would make most events seem designed so I do not believe that specification would help us out here.
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Rex Kerr
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posted 24. January 2003 23:23
My impression was that Dembski was speaking about the performance of the filter in the limit as scientific knowledge about natural processes tends to omniscience.
In the real world, everything produces false positives. People go through first-order predicate logic and get contradictions between two equivalent statements. We don't conclude that first-order predicate logic is problematic, or that we shouldn't use it to study scientific problems, or that it on its own has type-I and type-II errors! We conclude that everyone makes mistakes.
I am not quite willing to grant the filter "flaw-free" status; I've come up with some moderately perverse counterexamples that are explicitly random and yet are scored as designed by the filter. (Although one could charge that I designed the counterexample very carefully and that is what is being picked up; I haven't fully evaluated whether that is a relevant objection; it may be.) However, the garbage-in garbage-out principle applies to nearly everything. I'm not ready to fault the filter for having that characteristic.
(I will fault conclusions that are based on the assumption that the filter isn't subject to GIGO, though. And it seems to me as if error is skewed very heavily towards making the design inference when it is not warranted.)
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Cre8ionist
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posted 25. January 2003 08:51
Perhaps another approach,
Dembski's filter criteria includes contingency:
quote:
In practice, to establish that an object, event, or structure is contingent, one
must show that it is not the result of a natural law (or algorithm). For
example, a crystal of salt results from forces of chemical necessity that can be
described by the laws of chemistry. By contrast, a setting of silverware is not.
No physical or chemical laws dictate that the fork must be on the left and the
knife and spoon on the right. The place setting of silverware is therefore
contingent, whereas the structure of the crystal is the result of physical
necessity.
How could the circles be considered contingent by Dembski's definition?
The illustration of the scrabble pieces in the drain's vortex shows the difference to me.
In the case of the drain their structure/placement is specified by physical necessity, in the case of players on the board, intelligence. One's contingent, one's not!
Therefore you cannot rightly use the circles in Dembski's filter......Cre8
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