The SETI example

One of the most famous examples in the Intelligent Design debate is the SETI example. Apparently in the film Contact the scientists involved in SETI (Search for Extra Terrestial Intelligence) recieve a signal that is a string of prime numbers. Dembski argues that this, if it really happened, would be a clear indication that the signal was designed, because it is so incredibly unlikely that such a sequence would be generated by chance, and this shows that you can deduce design without knowing anything about the nature or intentions of the designer.

There has been a lot of criticism of this example ranging from this is not the way SETI actually hopes to detect intelligence to there is no probability distribution specificed for the distribution of numbers . But some of these criticism are beside the point. It doesn't really matter how SET actually operates. We can just think of it as a though experiment. Suppose we did receive a sequence of prime numbers what are the implications for detecting design?

The first thing to recognise is that we are in very strange territory here. No one in the history of mankind has had any experience of dealing with this kind of phenomenom and we cannot rely on our intuitive feelings of what is reasonable. Common sense may tell us "this was the product of an intelligent mind". But that is because we are used to seeing intelligent minds (our own) produce sequences like this and we understand how and why they do it. In this new world we must stick to strict logic.

The logic of the design argument is:

1) The sequence can only be the result of necessity, chance or design.
2) There is no law of nature that produces sequences like this. So necessity is ruled out.
3) The probability of getting this sequence by chance is so low as to be impossible. 4) Therefore there must be some element of design in the explanation.

I don't wish to dispute (1). Some people have argued that events are actually combinations of all three. But I think this is simply dealt with by describing the options as "pure necessity, chance+necessity, design+chance+necessity". We all recognise that designed solutions involve using the laws of nature and some estimates of probabilities as well.

(2) is unproven but we have to accept we don't know of any such law.

(3) This is where the logic begins to falls down. It has been thoroughly addressed by Richard Wein here. You cannot make this calculation without having a specific chance hypothesis on which to base the calculation. Dembski assumes without any real justification that all bit sequences are equally likely. We really have no idea. There may be natural processes that are quite likely to produce sequences of prime numbers. Who can tell? We have the whole universe to choose from. It is well known that when pulsars were first discovered it was seriously considered that they might be the product of some minds but then a natural explanation was discovered.

(4) This is where the logic gets really hazy. To dismiss chance and deduce design you not only have to calculate the probability of some explanation based on chance - you have to compare it to the probability of an explanation based on design. We are dealing with an extraordinary event (that hasn't yet been observed). Whatever the explanation, it is going to be pretty unlikely. And we have no knowledge whatsoever about possible explanations involving either chance or design.

In the film I understand that they deduce intelligence (I haven't seen it). That seems natural because we understand how and why a human intelligence might produce a sequence of prime numbers. But that is the only reason. There is no further logic behind it.

Continuation of a discussion from UD on bad design

I started a discussion about the implications of apparently poor design in life on UD. However, this is a banned subject on that blog so I am posting the discussion here and inviting the participants to continue.

Below is an edited version of discussion so far - you can see the full dialogue back on UD.

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1.

> Dr. Walter Fitch[’s] … main argument was that if intelligent design were true, then the human body should have been designed better to avoid disease and malady.

I have seen this argument used in more than one place recently. It puzzles me that anyone would consider this a strong argument yet it seems to have found a comfortable place in the evolutionists’ bag of tricks.

I’ll leave aside the theological argument, which would have little weight with most evolutionists, that our maladies are a result of mankind’s fall into sin. I don’t need to look any farther than the car in my driveway, which is due for service tomorrow, to realize that design in no way implies perfection. I am quite sure that my car is designed (intelligently for the most part). Yet… 1.) It may contain flaws in design or construction that result in less than optimal performance, 2.) If I fail to maintain it properly it will die an early death, and 3.) Even with the best maintenance it will eventually wear out and cease to function.

I am not the crispest cracker in the box so I may be missing something that is obvious to those with more intelligence, but it utterly escapes me why anyone living in a world full of designed yet imperfect objects would argue that design implies perfection, or conversely that a lack of perfection implies a lack of design.

SG

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2.

SG

The argument goes like this.

If there is a designer then they have made some very poor decisions from the organisms point of view - like having the optic nerve attach to the retina from inside the eye or the nerve that joins the brain to the larynx going round the heart and back!

It is possible that they are a poor designer or are deliberately making poor designs from the organisms point of view for reasons of their own.

However, this means that we are making no assumptions about the competence or motives of the designer and this in turn means that the explanatory power of design disappears i.e. the answer to the question - if life is designed then what would it look like? becomes - “well - anything could be designed”.

This removes any positive argument for design and it becomes purely the negative argument - “Darwin doesn’t work in some instances therefore it must be designed”.

Comment by Mark Frank — May 17, 2006 @ 12:33 am


This argument is affectionately ridiculed as “bad design means no design” and is on the list of arguments that get you banned here for bringing it up (read the comment policy on the sidebar). It is not a scientific argument. It argues against design by speculating about the quality of work a supernatural designer would or would not accomplish. In other words, it’s an argument from theology dependent on the purported goals, desires, and capabilities of a supernatural designer. Consider yourself warned and don’t bring it up again. -ds

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3.

In addition to the above comments, the design process involves a constant evaluation of contingencies. I can choose a stronger material, but then the cost increases significantly. I can decrease power output to resolve a potential heat issue, but then speed requirements may not be met.

Which decisions are best for the overall design? Perhaps only the designer knows. I can tell you, however, that evaluating a design based on singular or collective deficiencies (even if only perceived), without understanding the competing design requirements that were dictating direction, is not a sound way to go about it. Unfortunately, this seems to be typically how Darwinists handle this business.

Comment by ultimate175 — May 17, 2006 @ 8:21 am

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5.

I think Mark Frank’s comment (posted after I did) does a fine job of illustating my point.

Comment by ultimate175 — May 17, 2006 @ 11:53 am

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7.

Mark:

1. Any engineer will tell you that designers implement limitations to benefit performance of the overall system. When building complex machinery, it is necessary for certain components to be positioned sub-optimally for the overall performance of the end product. This is Engineering 101.

2. What is optimal design? What does it look like? How does it behave? How do we answer these questions without an absolute standard of optimality with which to juxtapose sub-optimal design? Tell me about the relationship of optimal designs to the law of entropy. How would “optimal” designs in nature impact predator-prey relationships, extinction and the ecosystem?

I think this paper will help you:

http://www.discovery.org/scripts/viewDB/index.php?command=view&id=86

Comment by Scott — May 17, 2006 @ 4:01 pm

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And here is my next response.

Scott, Ultimate175

I am sorry I did not make my point clear. I accept that design may be constrained or imperfect and still be design. My point is that if you do not make any assumptions about the standards or objectives of the designer then it is impossible to determine whether something is designed. To put it another way. If the ID hypothesis were that the designer always designs with the long term interests of the species in mind and is supremely good at its job - then the ID hypothesis has some limited meaning and is falsifiable. We can look at various aspects of life and where the function appears to be easily improved this counts as evidence against the hypothesis and if later it turns out that in fact the apparently poor function did have a justification that counts as support. I would still want to dispute how much meaning it gave to the ID hypothesis - but it would be a positive approach. An alternative might be to say that the designer actually concentrated only on a clearly described class of mechanisms. However, if you just say there is design but we don't know the purpose and we don't know the standard - well you don't have a falsifiable hypothesis and are reduced to negative arguments saying that Darwin is improbable therefore ID.

Dembski's paper is about the problem of evil but I am not concerned with that. The nerve connecting the brain to the larynx via the heart is nothing to do with religion or the problem of evil. It is just very inefficient.

So how would you teach science?

"Mike the Mad Biologist" has raised this interesting question on his blog. He is talking from an American point of view but I don't think it is so very different here. I am supposed to be studying science communication so I guess I ought to have a view.

His concern is mainly the level of scientific knowledge among non-scientists - or scientific literacy to use the jargon. I am not sure that formal learning in school with teachers is going to crack this. Even if we pay enormous salaries for teachers, there are only so many subjects that someone can study at school and science keeps on changing and accumulating. I suspect we should be thinking about how non-scientists learn about science all through their lives. School has a part to play but it is probably mostly about attitude and motivation - not knowledge or skills - and what motivates one person may turn another off. Some people will be turned on by the chance to do experiments; others by big ideas; and yet others may appreciate a history of science approach; or seeing science in use. The trick is try and accommodate all these differences and that takes careful planning.

But this then has to be followed up with excellent learning opportunities through life. More and more instituations and individuals do seem to take this seriously with some excellent results - popular science writing, TV, blogs, science centres. The missing elements are connecting people into all these resources, structuring the resources so they are not overwhelming and motivating people to use them.