Privileged Planet: Nature review

In addition to my reviews and evaluation of the Privileged Planet ideas, the book has now been reviewed in Nature by Douglas A. Vakoch from the SETI Institute. Titled “Bright blue dot” NATURE VOL 429 24 JUNE 2004 p 808-809

First some links to my reviews:

The Privileged Planet Part 1: Where Purpose and Natural Law freely Mix Part 1

The Privileged Planet Part 2: The failure of the ‘Design Inference’

The Privileged Planet Part 3: The Anthropic principle

and my response to Richard’s ‘response’ to Kyler Kuehn’s statements

Privileged Planet: The fallout starts

Now the review in Nature:

Ultimately, however, the authors are in a poor position to argue that Earth is optimally located for both habitability and measurability. They try to establish habitability requirements by comparing Earth with other locations in the galaxy.Unfortunately, we lack the data required for a well-reasoned comparison. If we had many examples of planets that do and do not bear life, and an explanation for why the conditions on some planets led to life while those on others did not,we might be able to establish an accurate metric of habitability. Until then, we are forced to extrapolate measures of habitability from a sample of one inhabited planet.

Not to mention that “the concepts of habitability and measurability have not been given quantifiable values”

Regrettably,any judgements of optimality may be biased by the local conditions and historical contingencies through which our life and our science have evolved, rather than accurately reflecting the range of possible preconditions for habitability and measurability. Potential readers of The Privileged Planet would do well first to familiarize themselves with the biases that can result from this kind of selective sampling. A good primer is Nick Bostrom’s Anthropic Bias (Routledge, 2002).

Yes, cherry picking is a good possibility. Exploring the full range of habitability and measurability is inherently limited to our knowledge and biased towards earth.

See more on this topic here

Caution seems especially in order given that the authors have intentionally limited themselves to our knowledge of the Universe gained through selected observational sciences, such as comparative planetary geology, solar physics and astronomy, rather than including more laboratory-based sciences. Similarly, although the authors attempted to avoid cherry picking instances of measurability that support their position by focusing on important observations in these fields, the vagueness of such a criterion makes their selection rather subjective. So far, Earth is the only planet we know that has the privilege of bearing life that searches for signs of other intelligence – whether in the form of other technological beings transmitting evidence of their existence or through patterns indicating underlying design. It may be some time, however, before we can accurately judge whether our blue dot is – as planets go – commonplace, unique or somewhere in between.

See also The Purpose of Life is a Beach Part 1

for a good example of ad hoc arguments of measurability, habitability and pleasurability.

I am sorry to hear that I missed the broadcast on

Dennis Prager show on march 25, 2004

And then there is the review at New which quite openly mentions “Origins from the perspective of Intelligent Design and Old Earth Creationism.”