Jan 07 2009

SETI vs Intelligent Design

Blogging for the Discovery Institute, Michael Egnor repeats the already debunked canard that the Search for Extraterrestrial Intelligence (SETI) is analogous to the search for Intelligent Design (ID) in nature. This time he is responding to a recent blog entry of mine on SETI. He doesn’t actually respond to any of my points – he is just using my entry as an excuse to repeat the SETI false-analogy.

Egnor writes:

One is struck by SETI supporters’ speculative extravagance. The most cogent critique of SETI, in my view, is that it is akin to an article of faith. There is absolutely no evidence for the existence of extraterrestrial life. SETI is surely a shot in the dark, perhaps literally, but I do believe that it is a worthwhile scientific venture. Methodologically it is certainly science, even good science. The reception of signals with specified complexity or the discovery of artifacts apparently crafted by intelligent non-human agency would be clear evidence for extraterrestrial intelligent agency. Carl Sagan’s example in “Contact” is entirely valid. The reception of a signal repeating prime numbers would be very unlikely to have a non-intelligent natural source, and the most reasonable scientific inference would be that it was generated by extraterrestrial intelligent life.

Apparently Egnor did not do what I just did prior to writing this entry – Google “SETI” and “ID”. If he did, the very first entry is an excellent article from 2005 by SETI researcher Seth Shostak deconstructing the SETI-ID analogy. Seth writes:

In fact, the signals actually sought by today’s SETI searches are not complex, as the ID advocates assume. We’re not looking for intricately coded messages, mathematical series, or even the aliens’ version of “I Love Lucy.” Our instruments are largely insensitive to the modulation–or message–that might be conveyed by an extraterrestrial broadcast. A SETI radio signal of the type we could actually find would be a persistent, narrow-band whistle. Such a simple phenomenon appears to lack just about any degree of structure, although if it originates on a planet, we should see periodic Doppler effects as the world bearing the transmitter rotates and orbits.


Well, it’s because the credibility of the evidence is not predicated on its complexity. If SETI were to announce that we’re not alone because it had detected a signal, it would be on the basis of artificiality. An endless, sinusoidal signal – a dead simple tone – is not complex; it’s artificial.

Seth makes an excellent distinction between “complex” and “artificial.”  Sometimes simplicity is more a sign of intelligence than complexity. But these types of states derive from a deeper logic – one that Egnor and his ID buddies completely miss. It is, in fact, the core fallacy of ID.

What Seth is saying is that we have prior knowledge of the kinds of radio signals that nature is capable of producing. Natural radio signals have a signature – they are inefficient, which operationally means that they are spread out over a wide spectrum. So far, this has always been the case. There is no known natural process that produces a narrow band transmission. Therefore, SETI is searching for such a narrow-band signal.

But there is a flip side to this that Seth did not discuss – not only do we have knowledge of what kind of radio signals nature can produce, we have knowledge of what kind of radio signals can be generated deliberately by an intelligent race that has achieved radio astronomy (namely us). We can therefore say that a known marker or signature of technologically produced radio signals can be an efficient narrow band.

This is key – SETI is searching for signals that not only cannot currently be explained by nature, but have a positive feature known to be a marker of intelligent artifice. Mere complexity is not enough – and for SETI screening purposes is not even in the equation.

Presumably, however, if SETI did find a candidate signal that had the markers of artifice and lacked a natural explanation, we would then take a closer look at the signal and look for encoded information. If we found it, how would we know if the information is the product of natural processes or deliberate intelligent artifice?

Well – we would go through the same process. Is there anything known in nature that can account for the information, and if not does the information contain any positive evidence or marker for artifice? One such marker of technological intelligence is mathematics. This is what leads to Carl Sagan’s idea that something like a series of prime numbers would be a possible intelligent tag in an ET signal.

We are using, here, ourselves as the only known (to us) model of technological intelligence. We make the reasonable inference that other technological intelligences would share in common with us (at least to some degree) mathematics and science. At least our respective civilizations would have independently tried to understand the same math and science – and it is reasonable to assume this would have led to some common understanding. It is likely, for example, that we would both measure the speed of light to be the same, and that on planet Vulcan (or whatever) 2+2 still = 4.

SETI, therefore, combines two criteria in its search for intelligence. The first is negative – finding an anomaly that cannot be explained by known natural processes. The second, however, is positive – finding that the signal has markers of technological intelligence, as best as we can infer from our solitary self-example.

Now, getting back to ID, Egnor writes:

Of course, if signals or artifacts that appeared intelligently designed were discovered in space, the scientific vetting of this data would include testing the inference that the artifacts arose by natural unintelligent means. That is, the design inference would be tested against the inference to natural unintelligent causation. This of course has been done in SETI; there have been instances (e.g. pulsars) in which signals that raised the question of design were investigated and found to have a natural unintelligent cause.

Yet, in SICI, the inference to design has not been vetted, and in fact, investigation of the obvious evidence for design has been ruled out in many established scientific circles. Why the widespread scientific resistance to SICI, which has produced abundant scientific evidence for design, but not to SETI, which has produced nothing of scientific value?

As usual, he is profoundly confused. (SICI, by the way, is his attempt to coin a new phrase – the Search for IntraCellular Intelligence – gag).  He is confused about how SETI works, as I described above. And also he is confused about the history of biology and evolution. SETI is vetted (partially) by ruling out natural causes. How would ID be vetted? He says it has not been – but in fact it has.

There is a natural explanation for the information we find in living organisms – that explanation is evolution. ID proponents and creationists, despite their best efforts, have not been able to hold back the flood of evidence and solid scientific reasoning that points to organic evolution as the source of biological complexity.

What is the evidence Egnor refers to for design in nature? He doesn’t bother to give even a single example. I can presume, however, that he is referring to so-called irreducible complexity (IC), the notion that some structures in biology are too complex to have evolved. IC, however, has been given a fair hearing in the court of science and was demolished. Purported IC structures and pathways have been shown not to be evolutionarily irreducible. ID proponents also ignore the many explanations for how complex structures may evolve – such as through gene duplication and coaptation.

In practice, and very much unlike SETI, ID is reduced to making an argument from ignorance (specifically the god-of-the-gaps argument). They argue (falsely) that evolution cannot explain certain aspects of life, and therefore that is evidence for ID. They are therefore restricted to the negative type of evidence I discussed above – ruling out a natural cause. And they fail at that. In fact all they do is assume what they endeavor to prove – that evolution does not explain life.

But more importantly from the point of view of what counts as legitimate science, ID has no positive argument to make for design. SETI, at least, can point to positive markers for technological origin. What are the positive markers for ID? There are none. ID proponents try to twist the negative criterion to make it sound like a positive marker (referring to IC or specified information) but it is still negative – meaning that it is based on the alleged inability to explain aspects of biology.

ID proponents cannot posit a positive marker for ID in nature because they refuse to make any statements about the designer. The designer, operationally, is omnipotent and unfathomable. We cannot say what a designer would do, or what a designed biology should look like. ID, apparently, can choose to make biology look like whatever we happen to find in nature. And therefore, ID makes no predictions about what we should find, and is therefore not falsifiable.

In other words – it’s not science.

Also – we can take Seth’s statement of the difference between complex and artificial and apply it to biology (as Seth briefly does himself in his article). From what we know so far it seems that inefficiency is a general marker of natural systems, and “narrow band” type efficiency is a marker of deliberate artifice. The information in DNA is not efficient. It’s a mess. It’s exactly what we would expect from a naturally self-organizing system. It does not reflect the elegant simplicity or efficiency of artifice.

I am not proposing this line of evidence as strong evidence for evolution by itself. But for what it’s worth – this one goes in the evolution column, not the ID column. Of course, if we look closely at DNA across species, we see the most powerful line of evidence for evolution – a branching pattern of relatedness that closely follows morphology.

In place of a cogent defense of ID (because one does not exist), Egnor give us only his tired standby:

The answer, I believe, is that the implications of SICI are unacceptable ideologically to many scientists, who are philosophically materialistic and hence unwilling to examine the evidence for design in biology from an unbiased perspective.

ID proponents would have you believe that the consensus of scientific opinion, hashed out over decades of transparent debate based upon a continuous stream of evidence, is the result of ideology. Meanwhile, the minority cultish beliefs of the Discovery Institute, which cannot hide their overt religious basis, is not ideological.

Egnor cannot manage a coherent argument, and utterly fails to grasp basic logic. So instead he resorts to endless whining about materialist ideology and bias.  At least he provides useful instruction as to the poor logic and tortured arguments of the the ID crowd.

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