(The Discovery Institute’s Center for the Renewal of Science and Culture used banners based on The Creation of Adam from the Sistine Chapel. Later it used a less religious image, then was renamed the Center for Science and Culture.)
In physics, the notion of fine tuning refers to the situation where a certain number of parameters must have a very precise value in order to be able to account for this or that observed phenomenon.
In cosmology, these considerations are at the root of what is called the anthropic principle: it seems that a variation, even a small one, of certain fundamental constants would not have allowed life to emerge in the universe. For example, life can not develop if the cosmological constant or the dark energy have values that are too high, because they would then prevent the mechanism of gravitational instability and consequently the formation of large structures. The smallness of the observed value of dark energy, compared to the value that seems most natural (corresponding to the Planck density, 10122 times higher than the observed value) is an example of fine adjustment.
It is possible that the recourse to the notion of fine adjustment reflects the difficulty for science to integrate both the Planck scale and the cosmic scale. Indeed, sixty temporal orders of magnitude separate Planck’s time, at 10-43 s, and the age of the Universe, at about 1017 s, and theoretical models generally accepted at the beginning of the twenty-first century are unable to include such a range of magnitudes in a unified scheme.
The notion of fine-tuned Universe, often used to demonstrate the strong anthropic principle, is one of the spearheads of the defenders of the spiritualistic thesis of intelligent design.
Fine tuning argument and theological explanation
Proponents of this hypothesis assume that the universe is created either by a teleological principle or by a conscious, intelligent being. For example, a God in the theological sense, is oriented towards a specific goal and the universe therefore has life-friendly conditions. There is a purposeful sense that may not be accessible because of the limitations of the human mind. This hypothesis is represented by the philosopher of religion, Richard Swinburne.
Intelligent design is a pseudo-scientific theory which claims that “certain observations of the universe and the living world are better explained by an ‘intelligent’ cause than by undirected processes such as natural selection”. This thesis was developed by the Discovery Institute, a conservative American Christian think-tank. Intelligent design is presented as a scientific theory by its promoters, but in the scientific world it is considered to be pseudo-science, by arguments as well internal to biology (the proponents of the intelligent design appearing to biologists as not taking into account many observations) than epistemological ones (in particular Karl Popper’s criterion of falsificability).
Most commentators and scientists see it as a resurgence of creationism, concealed under the appearance of scientificity; the British biologist Richard Dawkins even designates it as a “creationism adorned with a cheap suit”. Intelligent design is now classified in the United States in neo-creationist theories, especially following the publication of the Wedge document.
Intelligent design applies only to the field of biology, and does not deal with the origin of the Universe. Thus, it should not be confused with the anthropic principle. The main actors in the intelligent design movement accept a universe over 13 billion years old and the Big Bang theory, with the personal opinion that it is caused by the God of the Bible, but reject the mechanism of random mutation coupled with natural selection as a driver for the emergence of new species. William Dembski, one of the main founders of the Intelligent Design concept, recognizes the existence of solid evidence pointing to an ancestor common to all living species and is open to this idea, while Discovery Institute publications question this point or reject it, using mainly the creationist interpretation of the Cambrian explosion.
Criticism of fine tuning argument
The term “fine-tuning” is criticized: He is not a scientific term, but comes from the engineering sciences and is misleading because of its teleological connotation. In addition to objections that generally concern the validity of teleological hypotheses within scientific explanations, there are objections that reverse the arguments of teleology advocates. By way of example:
In the opinion of E. Sober, as well as M. Ikeda and B. Jefferys, the assumption of an otherwise unspecified creator is not an explanation for the fine-tuning, since this creator, powerful enough to create universes, could create life in a non-finely tuned universe. Even if in a universe none of the finely tuned constants would have the right size, it would certainly be possible for him to provide conditions in this otherwise hostile universe in a local place that would enable life. For example, if the interaction constants of the forces did not have the correct magnitudes, so that carbon-12 could not arise naturally, an almighty Creator could, by supernatural intervention, nevertheless create the carbon-12 necessary for life.
For M. Ikeda and B. Jefferys, this argument is a powerful affirmation of naturalism, with the assumption that everything in our universe is about “right things”, that is, in accordance with the law and without supernatural intervention. They just argue that the hypothetical observation that the universe is not just finely tuned, but even for life would be almost inappropriate, would not point to a creator. For only under the assumption that our universe behaves strictly in accordance with the law is there a need for a fine-tuning and that the need for divine-creative interventions and impulses is eliminated. However, it is argued that a possible creative force has, from the beginning created the laws of nature in such a way that they make life possible. The rational intelligibility of the universe is thus interpreted as an indication of the existence of a creative force. Representatives of this view are, for example, the mathematician and philosopher John Lennox or the human geneticist Francis Collins.
Both Richard Swinburne’s argument and the argument of M. Ikeda and B. Jefferys use Bayesian statistics for their argument, which is not universally accepted and, for example, rejected by representatives of an objective notion of probability. Even among adherents of Bayesian statistics, there is no agreement as to which type of hypothesis Bayesian statistics can be applied to. One of the best-known representatives of Bayesian statistics, B. de Finetti , limits the applicability of Bayesian statistics.