The Fine-Tuning argument

This Creationist argument proposes that the constants in physics are so precisely established to support life that the universe could only have been created by god. There is no way these constants could be accidental. To them, this proves that a personal god fashioned the universe so that humans could come into existence and worship him. This argument has much in common with two concepts in Cosmology known as the Weak Anthropic Principle and the Strong Anthropic Principle, though those principles are more philosophical in nature, and not explicitly religious:

One formal statement of the argument is:

1. The combination of physical constants that we observe in our universe is the only one capable of sustaining life as we know it.
2. Other combinations of physical constants are conceivable.
3. Therefore, some explanation is needed why our actual combination of physical constants exists rather than a different one.
4. The very best explanation of the given fact is that our universe, with the particular combination of physical constants that it has, was created out of nothing by a single being who is omnipotent, omniscient, all-loving, eternal, and interested in sentient organic systems, and that he "fine-tuned" those constants in a way which would lead to the evolution of such systems.
5. But such a being as described in (P4) is what people mean by "God."
6. Hence [from (P4) & (P5)], there is good evidence that God exists.

The atheist response:

• One response might be, "why is an explanation necessary?" There is no reason, within anything we currently understand about the ultimate structure of reality, to think of the existence and persistence and regularity of the universe as things that require external explanation. Indeed, for most scientists, adding on another layer of metaphysical structure in order to purportedly explain these fundamental facts is an unnecessary complication. We may discover even deeper levels of explanatory detail that underlie our current understanding, but there is no imperative that we arrive at anything resembling a complete explanation for existence right now.
• No one knows why the constants of physics have the values that they possess (the gravitational constant, the strengths of the weak and strong nuclear forces, the ratio of electron to proton mass, the energy density of empty space, and many others). It could be that there are no alternatives to these values, or if there are alternatives, they are within very narrow bands. We don't have enough information to state what the possible range of values for any of the constants are, so it is impossible to ascertain whether the actual values are likely or unlikely. To speculate about what it would take to find a universe where they are different is beyond our current understanding. Also, to assert that god had something to do with it is appealing to a god of the gaps - ascribing divine influence to yet another thing we don't yet understand. Science taught us about the constants, and science discovered their values. We would be wise to exercise some patience before jumping on the god hypothesis and give science a little more time to figure out where these values came from.
• Although there appears to be about two dozen physical constants that are considered to be fine tuned, science has only recently begun to understand these in any depth. Most particle physicists believe that there is another, more comprehensive theory that underlies the Standard Model of Quantum physics (such as String Theory, Quantum Gravity Loop Theory) that will simplify and reduce both the large number of particle and fundamental constants to a smaller, more manageable number. If such a theory is discovered, it may well be the case that instead of dozens of constants, we have just one.
• You can't say how likely something is or isn't from a sample size of one. We live in the only universe we know, so it is impossible to say if this is a likely universe or not, since we have no other ones to compare it to. We cannot point to other universes and note that they are lifeless and thus affirm that the appearance of life in our universe was so unlikely that a supernatural force had to jump start it.
• How does one use the fact that life exists as a proof of god? It proves nothing. It simply means that life is here. And even if you stipulate that a god created it, who is to say that is the Christian god? It could be some other god (or devil) from some other religion, or a god of no known religion, or an advanced Alien culture so far beyond us that we can't even comprehend their creation process. It could be that we are living inside an advanced simulation, which would explain why all the conditions are right for life. Any one of many unprovable and extreme possibilities could be true.
• We can freely admit that the fine tuning of the physical constants is baffling and intriguing. Physicists and cosmologists are fascinated with these. But instead of, once again, ascribing the things we don't understand to god's influence, this mystery should instead help focus scientific research. There is no doubt a very interesting order to how the universe is structured. Saying that god is responsible for it tells us absolutely nothing. It is just putting all of the unknowns into a black box labelled "god" and having done with it. Instead, we should (and we will) dig in deeper. I have no doubt that in the coming years we will know more about these constants than we do today.
• If god is responsible for all of existence, and if the point of the universe is for Humans to come into being so they could have a relationship with god, and god had an interest in sentient organic systems, why did he take so long to bring them about? And why did he confine his efforts to the planet earth?
• Some say that if a very small change were made to one of the physical constants, life could not exist. For instance, if the strong force (the nuclear coupling force) were 2% stronger than it is, diprotons would be stable and hydrogen would fuse into them instead of deuterium and helium. This would drastically alter the physics of stars, and presumably preclude the existence of life similar to what we observe on Earth. However, if that would have happened (or any of a number of other small changes) then there would be no life, certainly no intelligent life, and no one here asking these questions. So, it is not surprising to find ourselves here, since here is the only place we could be. Of course the universe has intelligent life in it. It would have to in order to generate beings such as us which can ask this question. In any alternative universe where life did not come about, there would be no one to ask it. In that light, it is not that unusual that we find ourselves in a universe capable of sustaining life, even intelligent life, capable of asking metaphysical questions. If the universe had turned out any differently, we would not be here to even ask the question. So, naturally we are in a universe that supports life. We would not be here if this were not the case.
• (From "cdk007 fine tuning" on the web) The universe is mostly very unsuitable human life, or life of any kind. We occupy a small portion of a very thin shell on a single planet in the entire universe. Our presence in the universe is infinitesimally small. To give a sense of proportion, it is analogous to saying that if on 3.5 billion Moon-sized planets we found only a single virus, that those planets were fine-tuned for life! Likewise, it is proportionally similar to having 6 million Olympic swimming pools that collectively contained a single water molecule, and asserting that those pools were fine-tuned for water storage. That is not very fine tuned at all! If the universe were really fine tuned for life, it seems there would be far more of it. In fact, the vast majority of the universe is poisonous, deadly, and hostile to life of all kinds! And also, consider that the span of time humans have lived on Earth is only a small fraction of the elapsed time of the universe. If the age of the universe were a 24 hour clock, Homo Sapiens would have lived just a fraction of a second on that clock. How can the universe be designed for human life, when we have occupied such a minute sliver of its entire spatial and temporal span?
• Some physicists speculate that there may exist parallel universes - that our universe is part of a "multiverse". Each universe in the multiverse would have its own laws of physics and values for the physical constants. Our universe just happens to have the laws and constant values that we find in it. Each universe would be equivalent to the roll of a die. Given an infinite number of universes, one would eventually be created that looks like ours. Some of these would be able to support life, but the vast majority would probably not (or at least not support life as we know it). Because we are intelligent beings, we are by definition in a universe that can support life. Because life would self-select for a universe such as ours, it should not be surprising that we should find ourselves here. Obviously this is all unproven and still being investigated. It should be noted that the multiverse theory did NOT come about as a response to the fine-tuning argument. It was a natural outcome, and predicted by, quantum theory. Numerous physics theories independently point to such a conclusion. In fact, some experts think the existence of hidden universes is more likely than not. It does fit as a possible explanation for why the constants are what they are, but was definitely not contrived just to fit as a response to the fine-tuning argument. It is not currently possible to see these other universes (if they exist), though some experiments involving new analysis of Cosmic Microwave Background have been proposed. The theory does, however, provide an explanation for the state of our particular universe.
• If anything, the excessive amount of tuning that characterizes the immensity of the universe is a bigger problem for the god explanation than for a non-god explanation. If the point of arranging the universe was to set the stage for the eventual evolution of intelligent life, why all the excess represented by the universe’s hundred billion galaxies? Are those other galaxies really necessary for life on Earth? Are they just a side effect of the Big Bang? Was it easier for god to toss those into the mix than to not have them, and if so, does god have to choose the easy route if he is capable of anything? Actually, cosmologists have calculated this - it turns out that almost all other possible histories of the universe that involve Earth as we know it don’t have any other galaxies at all! It’s unclear why God would do so much more fine-tuning of the state of the universe than seems to have been necessary.
• Given the universe that we have, it is not fine tuned for life, rather life is fine tuned for the universe. Given any universe capable of forming matter and having chemistry, and producing life, that life will compete and evolve over generations, bettering itself to survive in that universe.
• It may be that life and intelligence is more generic than we think. It might be the case that in a universe with different constants, a different sort of life may have formed, based on different fundamental principles.
• Many theists believe that life came about by a miracle from god. But if that is the case, then the universe was never fine tuned for life in the first place. According to them, the fact that life exists is literally is a miracle. If the universe was fine tuned just so life could exist, then life would have required no miracle - it would have arisen out of the perfect, fine-tuned, environment which was created specifically for it. Was it fine tuned "almost enough" for life, and just required a little miraculous nudge to get going? If god is real, he could have made life arise spontaneously in this universe, or allowed life to come about any any universe whatsoever, under any conditions, fine tuned or not. So, how can theists look at the conditions in the universe and say that they are evidence for god? Requiring a miracle for life to come about, and also insisting that the universe if fine tuned are contradictory positions.
• The discovery of the existence of these fine tuned constants, as is everything related to astronomy, cosmology, and the search for the origin of the universe, came from theoretical and empirical scientific efforts. Future discoveries that shed light on these issues will also come from these same types of efforts. This is an area that has never been moved forward by religion and armchair philosopy. In fact those have done nothing but to cause us to stagnate and become attached to old and incorrect ideas. We don't know how to unravel the mysteries of the physical constants today, but it is practically certain that input from the religious community is not going to help move the base of knowledge forward.
• Just looking at the prior probability of a god who did all this tuning, we seem to live in a universe that is very different from what I would expect if a god were in charge of putting it all together. One would have expected a far different reality than what we have. There are billions of worlds in billions of galaxies, but humans (who Christians seem to think are the whole point of the universe) live on one small world. Very wasteful. And why would a god with a plan for life come up with a solution that required 14.7 billion years for life to evolve, and to evolve in such a haphazard and seemingly undirected manner. Why would the process of evolution (which is how life is transformed) rely on a mutation process which generates thousands of destructive mutations for every beneficial one? Why would god, the chief executive of the universe, provide such shoddy and ambigous instructions (in the bible and other religious texts) that would cause his worshippers to fight wars over them for the last several millenia? And then after providing such shabby and unclear direction, punish those who didn't know what he was talking about by sending them to hell forever? And to allow all the random suffering and evil that exists. A simple reason is that there is no god, and the bible is the work of men - not the inspired word of god. The Christian religion is the creation of flawed and simple uneducated primitive men two thousand years ago.

Religion has never taught us anything about the structure of the universe. In fact pretty much all the statements that religion has made about physical reality have been shown to be wrong. All this information about physics, the constants, and the cosmos have come from science, not religion. So, I will look to science for any new information about how the universe is organized, about how to interpret the physical constants and determine what they mean. I will look to science to clarify the universe's initial starting conditions, and to shed light on why the universal constants have the values that they do. I certainly won't look to religion. It has been wrong since the childish and naive Genesis story, Noah's flood, Moses parting the red sea, Jonah living inside a "big fish" for 3 days, stars affixed to a solid firmament, and the sun stopping in the sky. Religion is the last place I would look for guidence about how the universe works. It should stick to its particular areas of expertise: singing hymns, hosting bingo games, praying, and the rest.

Finally a paraphrased quote from a counter-apologist podcaster who I follow, Justin Shieber:

Assuming the truth of the existence of a first cause who created the universe and finely-tuned its constants, and absent any argument showing that there is a statistically significant correlation between an interest in tuning-based activities and the practice of necromancy among an acceptable sample size of deities, I see no reason whatsoever to expect that a deity fond of fine-tuning should also be fond of the activities of one species of primate (us), and in particular raising first-century preachers from the dead.