[5] In 1913, chemist Lawrence Joseph Henderson wrote The Fitness of the Environment, one of the first books to explore fine tuning in the universe.
[6] In 1961, physicist Robert H. Dicke argued that certain forces in physics, such as gravity and electromagnetism, must be perfectly fine-tuned for life to exist in the universe.
[14] Among scientists who find the evidence persuasive, a variety of natural explanations have been proposed, such as the existence of multiple universes introducing a survivorship bias under the anthropic principle.
The standard model of particle physics has 25 freely adjustable parameters and general relativity has one more, the cosmological constant, which is known to be nonzero but profoundly small in value.
[17] Without knowledge of this more complete theory suspected to underlie the standard model, it is impossible to definitively count the number of truly independent physical constants.
[1][18] Max Tegmark argued that if there is more than one time dimension, then physical systems' behavior could not be predicted reliably from knowledge of the relevant partial differential equations.
[24] According to one calculation, if the state's energy level were lower than 7.3 or greater than 7.9 MeV, insufficient carbon would exist to support life.
Some versions of the multiverse hypothesis therefore provide a simple explanation for any fine-tuning,[5] while the analysis of Wang and Braunstein challenges the view that this universe is unique in its ability to support life.
[31] The multiverse idea has led to considerable research into the anthropic principle and has been of particular interest to particle physicists because theories of everything do apparently generate large numbers of universes in which the physical constants vary widely.
[40] Graham Priest, Mark Colyvan, Jay L. Garfield, and others have argued against the presupposition that "the laws of physics or the boundary conditions of the universe could have been other than they are".
[49] Scientist and theologian Alister McGrath observed that the fine-tuning of carbon is even responsible for nature's ability to tune itself to any degree.
The entire biological evolutionary process depends upon the unusual chemistry of carbon, which allows it to bond to itself, as well as other elements, creating highly complex molecules that are stable over prevailing terrestrial temperatures, and are capable of conveying genetic information (especially DNA).
[50][51]Theoretical physicist and Anglican priest John Polkinghorne stated: "Anthropic fine tuning is too remarkable to be dismissed as just a happy accident".
[56] Philosopher and theologian Robin Collins argues that theism entails the expectation that God would create a reality structured to realize a positive, and if possible optimal, balance of good over evil.
Thus it is not surprising, Collins contends, that we can find moral or aesthetic value in the world's features, such as the elegance and harmony of the laws of nature.