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Fine Tuning

Recently, many physicists and cosmologists have argued that there is quite a problem in how our cosmic environment manages to be one in which Darwinian evolution can operate over long ages to produce living beings. The cosmic period known to us began with a Big Bang. It looks as if the early cosmic density, and the associated expansion speed, needed tuning with immense accuracy for there to be gas clouds able to condense into stars: tuning to perhaps one part in a trillion trillion trillion trillion trillion. Further, the strength of the nuclear weak force had to fall inside narrow limits for the Big Bang to generate any hydrogen (which was needed for making water and for long-lived, stable stars like the sun) and for the creation of all elements heavier than helium. Also the strength ratio between electromagnetism and gravity needed extremely accurate tuning, perhaps to one part in many trillion trillion, for there to be sun-like stars. Again, the existence of chemistry seemingly demanded very precise adjustment of the masses of the neutron, the proton and the electron.

In a book of mine, Universes (1989), I made a long list of such claims about fine tuning. No doubt some of the claims will turn out to be wrong. For instance, it might be that the early cosmic expansion speed was more or less forced to be what it was, because of a process known as “inflation”, and the people who think that inflation itself needed very precise tuning could be mistaken. What is impressive, I suggest, is not any particular one of the claims about fine tuning, but the large number of claims which seem plausible, and the consequent implausibility of thinking that every single claim is erroneous. Here, then, we might be thought to have evidence of design, provided we judged that such design would have been directed towards producing living beings in a non-miraculous fashion through making the world obey physical laws which led to the existence of stable stars, planets, and an environment with a rich chemistry in which life could evolve.

Contributed by: Dr. John Leslie

Cosmic Questions

Was the Universe Designed? Topic Index
The Meaning of Design

Fine Tuning

The Argument from Design
Design and Living Beings
Design and Divine Conservation
Fine Tuning and the Laws of Nature
Anthropic Principles
The Best of All Universes
Design and Human Survival
A Platonic Approach
Spinoza's Compromise


John Leslie

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