Fine-tuned Universe - Disputes Regarding The Existence and Extent of Fine-tuning

Disputes Regarding The Existence and Extent of Fine-tuning

Computer simulations suggest that not all of the purportedly "fine-tuned" parameters may be as fine-tuned as has been claimed. Victor Stenger has simulated different universes in which four fundamental parameters are varied. He found that long-lived stars could exist over a wide parameter range, and concluded that "... a wide variation of constants of physics leads to universes that are long-lived enough for life to evolve, although human life need not exist in such universes".

Fred Adams has done a similar study to Stenger, investigating the structure of stars in universes with different values of the gravitational constant G, the fine-structure constant α, and a nuclear reaction rate parameter C. His study suggests that roughly 25% of this parameter space allows stars to exist.

The validity of fine tuning examples is sometimes questioned on the grounds that such reasoning is subjective anthropomorphism applied to natural physical constants. Critics also suggest that the fine-tuned Universe assertion and the anthropic principle are essentially tautologies. The fine-tuned Universe argument has also been criticized as an argument by lack of imagination, as it assumes no other forms of life, sometimes referred to as carbon chauvinism. Conceptually, alternative biochemistry or other forms of life are possible. In addition, critics argue that humans are adapted to the Universe through the process of evolution, rather than the Universe being adapted to humans (see puddle thinking). They also see it as an example of the logical flaw of hubris or anthropocentrism in its assertion that humans are the purpose of the Universe.