Denton tries to explain the connection between the fine-tuning argument and structuralism in a recent post on Evolution News & Views: Natural Life: Cosmological Fine-Tuning as an Argument for Structuralism. I've dealt with structuralism already [What is "structuralism"?] so let's think about fine tuning.
The essence of the fine-tuning argument is that the basic laws of physics and chemistry are so precise that even slight changes would result in a universe where life is impossible. The focus is usually on the fundamental constants such as the speed of light and the charge on an electron. I don't know enough about physics to evaluate the argument that these are fine-tuned so I have to rely on physicists to inform me.
I could rely on people like Michael Denton and other fellows of the Discovery Institute but past experience in areas where I am well-informed suggests that they are not a trustworthy source of information.
Here's what Denton says,
The 20th-century cosmological evidence that the universe is fine-tuned for life is based on the observation that if the various fundamental forces and constants which determine the structure of the cosmos and the properties of its constituents did not have precisely the values they do, there would be no stars, no supernovae, no planets, no atoms, and certainly no life.Is this correct?
Only four parameters are needed to specify the broad features of the universe as it exists today: the masses of the electron and proton, and the current strengths of the electromagnetic and strong interactions. (The strength of gravity enters through the proton mass, by convention.) I have studied how the minimum lifetime of a typical star depends on the first three of these parameters. Varying them randomly in a range of ten orders of magnitude around their present values, I find that over half of the stars will have lifetimes exceeding a billion years. Large stars need to live tens of millions of years or more to allow for the fabrication of heavy elements. Smaller stars, such as our sun, also need about a billion years to allow life to develop within their solar system of planets. Earth did not form until nine billion years after the big bang. The requirement of long-lived stars is easily met for a wide range of possible parameters. The universe is certainly not fine-tuned for this characteristic.Stenger goes on to quote other physicists who have done the same simulations and come up with similar conclusions. The universe is not fine tuned.
One of the major flaws with most studies of the anthropic coincidences is that the investigators vary a single parameter while assuming all the others remain fixed. They further compound this mistake by proceeding to calculate meaningless probabilities based on the grossly erroneous assumption that all the parameters are independent. In my study I took care to allow all the parameters to vary at the same time.
I have to trust an authority on this one. I choose to trust physicist Victor Stenger who has actually done an experiment to test the hypothesis of fine tuning.
I conclude that fine tuning is not a valid argument for the existence of gods.
It's even more complicated than that. Apparently the "constants" aren't even constant. Here's how Stenger explains it (page 147). He's referring to a, the fine structure constant that determines the strength of the electromagnetic force ...
However, a is not a constant. We now know from the highly successful standard model of particles and forces that a and the strengths of the other elementary forces vary with energy and must have changed very rapidly during the first moments of the big bang when the temperature changed by many orders of magnitude in a tiny fraction of a second. According to current understanding, in the very high-temperature environment at the beginning of the big bang, the four known forces were unified as one force. As was discussed in the previous chapter, the universe can be reasonably assumed to have started in a state of perfect symmetry, the symmetry or the "nothing" from which it arose. So, a began with its natural value; in particular, gravity and electromagnetism were of equal strength. That symmetry, however, was unstable and, as the universe cooled, a process called spontaneous symmetry breaking resulted in the forces separating into the four basic kinds we experience at much lower energies today, and their strengths evolved to their current values. They were not fine-tuned. Stellar formation and, thus, life had to simply wait for the forces to separate sufficiently. That wait was actually a tiny fraction of a second.If Stenger is correct, then the fine-tuning argument loses much of its potency. Can Intelligent Design Creationists refute the views of Stenger and other physicists or have they just convinced themselves that what they say to each other is true?