The Argument From Cosmic Fine Tuning

The concept of cosmic fine tuning relates to a unique property of our universe whereby the physical constants and laws are observed to be balanced on a ‘razor’s edge’ for permitting the emergence of complex life. The degree to which the constants of physics must match precise criteria is such that a number of agnostic scientists have concluded that indeed there is some sort of transcendent purpose behind the cosmic arena. British astrophysicist Fred Hoyle writes: “A common sense interpretation of the facts suggests that a super intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature. The numbers one calculates from the facts seem to me so overwhelming as to put this conclusion almost beyond question.”

Fundamental Constants

The ripples in the universe left over from the original ‘Big Bang’ singularity (often referred to as CMB, or cosmic background radiation) are detectable at one part in 10^5 (100,000). If this factor were even slightly smaller, the cosmos would exist exclusively as a collection of gas — stars, planets and galaxies would not exist. Conversely, if this factor were increased slightly, the universe would consist only of large black holes. Either way, the universe would be uninhabitable.

Another finely tuned value is the strong nuclear force that holds atoms — and therefore matter — together. The sun derives its ‘fuel’ from fusing hydrogen atoms together. When two hydrogen atoms fuse, 0.7% of the mass of the hydrogen atoms is converted into energy. If the amount of matter converted were slightly smaller — say, 0.6% instead of 0.7% — a proton would not be able to bond to a neutron and the universe would consist only of hydrogen. Without the presence of heavy elements, planets would not form and hence no life would be possible. Conversely, if the amount of matter converted were increased to 0.8% instead of 0.7%, fusion would occur so rapidly that no hydrogen would remain. Again, the result would be no planets, no solar systems and hence no life.

The ratio of electrons to protons must be finely balanced to a degree of one part in 10^37. If this fundamental constant were to be any larger or smaller than this, the electromagnetism would dominate gravity — preventing the formation of galaxies, stars and planets. Again, life would not be possible.

The ratio of the electromagnetic force to gravity must be finely balanced to a degree of one part in 10^40. If this value were to be increased slightly, all stars would be at least 40% more massive than our Sun. This would mean that stellar burning would be too brief and too uneven to support complex life. If this value were to be decreased slightly, all stars would be at least 20% less massive than the sun. This would render them incapable of producing heavy elements.

The rate at which the universe expands must be finely tuned to one part in 10^55. If the universe expanded too fast, matter would expand too quickly for the formation of stars, planets and galaxies. If the universe expanded too slowly, the universe would quickly collapse — before the formation of stars.

The mass density of the universe is finely balanced to permit life to a degree of one part in 10^59. If the universe were slightly more massive, an overabundance of deuterium from the big bang would cause stars to burn too rapidly for the formation of complex life. If the universe were slightly less massive, an insufficiency of helium would result in a shortage of the heavy elements — again, resulting in no life.

Mass of the Cosmos

The density of protons and neutrons in the cosmos relates to the cosmic mass density. That density determines just how much hydrogen fuses into heavier elements during the first few moments after the origin of the universe. In turn, the amount of heavier elements determines how much additional heavy-element production occurs later in the nuclear furnaces or stars.

What would be the consequence if the respective density of neutrons and protons were significantly lower? Firstly, nuclear fusion would occur with less efficiency. Consequently, the heavier elements such as carbon, nitrogen, oxygen, phosphorous, sodium and potassium — all of which are essential for the emergence of physical life — would not be formed. Moreover, assuming no additional cosmic density factors such as dark energy, a cosmos which possesses less mass density would prohibit the formation of stars and planets. Why? The expansion rate would be so big that matter would expand too quickly for gravity to pull together the gas and dust to allow their formation. If that were not enough, with only a little extra mass, the cosmos would expand so slowly that all stars in the cosmos would quickly turn into black holes and neutron stars. The density near the surface of such bodies would be so enormous that molecules would be impossible. Therefore, life would not be possible. The radiation from the formed black holes and neutron stars would also render physical life an impossibility at any point in a universe with such a high density.

Conversely, what would be the effect if the density of protons and neutrons in the cosmos were to be significantly higher? Nuclear fusion would be too productive, meaning that all the hydrogen in the universe would rapidly fuse into elements heavier than iron. The ultimate result is the same — the life-essential elements would not exist. Moreover, if the cosmic mass density were to be greater, gas and dust would condense so effectively under gravity’s influence that all stars would be much more massive than the Sun. Thus, planets would not be life-permitting because of the intensity of the radiation of their respective star, and additionally because of the rapid changes in the stars’ temperature and radiation.

The mass of the universe exhibits cosmic fine tuning to simultaneously permit two features which are essential for permitting life: (1) the correct diversity and quantity of elements; and (2) the appropriate rate of cosmic expansion required to allow life. Such cosmic fine-tuning bespeaks foresight and planning — indicators of intelligent design.

Our Place in the Universe

There exist many physical factors that must be precisely set for any planet to be hospitable to life. Life must be in the right type of galaxy. There are three types of galaxies (elliptical, irregular and spiral). Elliptical galaxies lack the heavy elements needed to support life. Irregular galaxies have too many supernova explosions. Only spiral galaxies can foster life. The Milky Way is a spiral galaxy.

Life must also be in the right location in the galaxy. We are situated in the right place in the Milky Way. If we were too close to the centre of the galaxy (closer to the black hole), harmful radiation would make life impossible. Conversely, if our planet was too far out in the periphery, not enough heavy elements would be available for the construction of habitable planets.

Life must also have the right type of star. Stars act as energy sources for life. Most stars are too large, too bright or too unstable to support life. The size and age of the sun enhances the earth’s hospitality. If the earth were moved 1% closer to the sun, bodies of water would vaporize, and life would not be possible. If the earth were as much as 2% farther from the sun, its waters would freeze. Earth has a nearly circular orbit, which ensures a nearly constant distance from the sun — ensuring that seasonal changes are not too severe.

The other planets in our solar system contribute greatly to earth’s habitability. For example, the massive gas giant Jupiter acts as a cosmic vacuum cleaner, protecting the earth from incoming comets. Likewise, Mars protects the earth from incoming asteroids.

If earth did not have a moon of the right shape and size, our planet would not be able to sustain life. The moon stabilizes the earth’s tilt, in turn preventing extreme temperatures and creating a stable, bio-friendly environment.

There are many other factors which influence the habitability of the earth. The few examples here detailed unequivocally demonstrate that indeed the earth is a privileged planet, another indicator of intelligent design.

Is the Universe Designed for Discovery?

In 2004, Guillermo Gonzalez and Jay Richards published their groundbreaking book, “The Privileged Planet”, in which they argued that the conditions most suited for life also provided the best overall setting for making scientific discoveries. In other words, our planet is not merely fine-tuned for life, but it is also finely-tuned for discovery.

One example is the phenomenon known as solar eclipses. People have witnessed solar eclipses for millennia, but only recently have we begun to notice a remarkable correlation: The only place in our solar system where a perfect solar eclipse can be observed happens to be the only place where there are observers. There are hundreds of moons in our solar system, but most moons cannot entirely eclipse the sun. Of all the places in our solar system, only on earth do the sun and moon appear the same size to observers. This is because the sun is both approximately 400 times larger than the moon and roughly 400 times farther away. Solar eclipses have played a significant role in scientific discovery, having helped physicists to confirm Einstein’s general theory of relativity.

The Milky Way, as a spiral galaxy — in addition to being the only biofriendly kind of galaxy — is relatively flat. Consequently, it has less gas and dust than others, and fewer stars impede our view of the rest of the universe.

Earth is located not only in the galactic habitable zone, but also in the right place where minimal light pollution and other visual obstructions might impede the view of our surroundings. Moreover, earth’s atmosphere — which is the only one we know of which can support life — is also the only one clear enough to allow us to observe the universe.

Such findings place naturalists (who see us and our place in the cosmos as nothing more than accidents) in an uncomfortable position. But it makes a lot of sense to theists, who see us and our place in the cosmos as fully intended by an intelligent creator.


To believe that the facts and figures here detailed amount to no more than happy coincidence, without doubt constitutes a greater exercise of faith than that of the Christian who affirms the theistic design of the universe. Such scientific insights over the last several decades have led the late Robert Jastrow — a self-proclaimed agnostic — to write: “For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries.”

This blog post was adapted from a previous article published on

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21 replies
  1. Allen Hainline says:

    Great post Jonathan! I think a clarification is needed though in the discussion of how the density of the early universe affects the formation of heavier elements. Fine-tuning is definitely required to avoid disaster in the combined expansion rate/density – without this fine-tuning the universe would have had either a runaway expansion or a recollapse before any life could survive. However, Big Bang nucleosynthesis created only H, He, and Li – all of the heavier elements up to Fe were created in stellar fusion. Of course other fine-tuning is also involved in this process – the extreme fine-tuning required to produce carbon and oxygen is a key factor that led Hoyle to make the comment you quote. Hawking says in Grand Design that the constants of physics seem to have been set so as to maximize the number of stable elements.

    We should probably also address inflation since some argue that this does away with the need for a finely-tuned cosmic density in the early universe. However, many physicists have documented how inflation itself requires fine-tuning. Recently Sean Carroll of Cal Tech noted that “the fraction of realistic cosmologies that are eligible for inflation is ” 1 in 10 to the 66,000,000 power.

  2. Martin says:

    Even if one accepts the the premis that cosmic fine tuning suggests an intelligence, one cannot conclude that this intelligence is a deity of any sort. That bridge is utterly nonexistent.

  3. Just Thinking says:

    Martin – so if the source of the “intelligence” is not a deity, who (or what) was able to implement this fine-tuning on a cosmic scale?

  4. Martin says:

    @ JT- Assuming there was an intelligence behind the fine tuning, no one knows who this “being” was or was not. There is no reason to ascribe the term “deity” to it, if such a being exists.

    In other words, just becuase a being might have created all that now exists, it does not follow that this being is what you might think of as a god.

    There is no implied theology.

  5. Allen Hainline says:

    I think that the fine-tuning argument leads directly to a very powerful uncreated being. Any created being would have come about too late to setup the underlying physics. Any being capable of setting the laws of physics and determining how to set the various constant governing the laws, masses of particles, etc. would have to be ridiculously wise and powerful. In fact, the fine-tuning of the initial conditions of our universe is estimated to be to 1 part in 10 to the power of 10 to the power of 123 (by Oxford physicist Roger Penrose). The arrangement of particle in this extremely early phase of the universe would have had to have been more precise than Heisenberg’s uncertainty principle would allow – so literally impossible for any being limited by physics. In fact, Planck’s constant (which governs this principle) is itself one of the finely-tuned parameters (and in multiple concurrent, independent ways).

    Of course, there are other steps to get to the Christian God but this argument provides strong evidence against atheism. Other evidence is discussed in other articles on this website – e.g. for the resurrection of Jesus, fulfilled prophecy, religious experience, etc. Christianity stands head and shoulders above other religions in standing up to critical inquiry.

  6. Martin says:

    //Of course, there are other steps to get to the Christian God but this argument provides strong evidence against atheism.//

    Allen, you did not outline any steps to get to the Christian god, nor did you provide any evidence, strong or otherwise, against atheism.

    Again, even if one accepts the the premis that cosmic fine tuning suggests an intelligence, one cannot conclude that this intelligence is a deity of any sort. Such a being would be, no doubt, powerful, but there is no reason to frame this being in terms of a god/deity.

    //Christianity stands head and shoulders above other religions in standing up to critical inquiry.//

    This is not a valid argument in support of Christianity. It in fact immediately undermines Christianity. All this does is put Christianity in the same basket together with all other religions to which you ascribe exactly zero credibility. How strong a statement… how strong an endorsement of Christianity is this really?

    An analogous statement for you: An inchworm stands head and shoulders above the common garden snail in when tested for top velocity.

    Go little inchworm…. go.

  7. Allen Hainline says:

    Martin, the point was that evidence such as the exceedingly low entropy in the early universe does point to a divine Creator since it would be physically impossible for a being Himself limited by the laws of physics to arrange the particles so as to allow the formation of stars and planets. Can you suggest how a non-deity could set Planck’s constant, the speed of light, the gravitational constant, the mass of an electron, etc.? This doesn’t seem much more plausible than fine-tuning “initial conditions.” The words of one of my former physics profs may be troubling here to the skeptic who thinks that we may later discover some physics principle to explain this: “Never has physics come up with a way to tell with what initial conditions the universe was started off. On nothing is physics clearer than what is not physics” John A. Wheeler

    I wasn’t trying to argue for Christianity but more listing other types of arguments that persuaded me. I really was just wanting to interact with arguments and evidence related to the original post. Other blogs would be more appropriate for interacting with other evidence.

  8. Martin says:

    Allen, I suppose my objection lies in your using terms such as “deity” and “divine”. To me, these words connote religion/theism, and so your argument becomes, by default, an argument for religion.

    I didn’t oppose your idea that the universe could have conceivably been started by an intelligence/being. My point was only that there is no reason to think of this being as a “divine Creator” or a “deity” or a “god”.

    When you said “Of course, there are other steps to get to the Christian God”, I assumed you had been trying to make a case to that end.

    Actually, I did make the second observation that your argument, not having made a clear case for a divine Creator (or god of some sort), did not provide strong evidence against atheism, as you had asserted.

    The argument from cosmic fine tuning, in my vew, could suggest an intelligence/being, but it doesn’t suggest a divine deity or a god. I don’t see how one can arrive at a theistic god from this argument.

  9. psiloiordinary says:

    It is a rather large leap from deism to theism.

    Nothing in this post or the ensuing discussion appears to offer any kind of a bridge.

  10. Stephen B says:

    PSI, I think it’s fair enough to say “Here’s my argument for a God”, and then move from that to arguments for personal Gods elsewhere. Criticising the argument for not getting you to theism is like a creationist criticising Darwin’s theory of evolution for not explaining biogenesis.

  11. Martin says:

    Stephen B…

    //I think it’s fair enough to say “Here’s my argument for a God”, and then move from that to arguments for personal Gods elsewhere.//

    How do you get from an intelligent creator, presumably responsible for cosmic fine tuning, to a god?

  12. Psiloiordinary says:

    Hi Stephen,

    Are you suggestion that the writer and other commenters admit this is not evidence for their god?


  13. Stephen B says:

    If you want to argue that John murdered Dave, and you’re trying to convince someone who doesn’t even accept that Dave is dead, the first thing you might try to do is show them the DNA sample of a corpse, right?

  14. Allen Hainline says:

    Note that I did give arguments for implausibility of any non-deity to fine-tune at least some of the laws and initial conditions. To elaborate, it is implausible that a physical being could set the arrangement of particles in our early universe for several reasons:

    1) The size of the early universe was too small to contain an intelligent being
    2) The temperature and extreme energies of the early universe would have incinerated any physical being (much hotter than the interior of stars)
    3) Based on 1&2 and other considerations, the intelligent being(s) would have to be outside the spacetime of our universe. However, then it becomes impossible for any physical being to causally affect our universe
    4) Even if such a being could causally affect our universe, the Heisenberg uncertainty principle would have had to have been violated to set the particles in precise enough locations/momentums to allow a highly structured universe to arise (as opposed to a universe dominated by black holes).

    Therefore the being(s) that finely-tuned our universe could not have been physical – sounds a lot like God to me and would at least qualify as evidence against atheism. I could have also argued that there is no known physics that would allow a physical being to have set the masses of fundamental particles, the force strengths, etc. Speculative theories within physics for how these might change are not conducive to being set by any physical being – e.g. in String Theory, the manner in which 10 spatial dimensions become compactified results in different constants but it’s implausible to think a non-deity could control such a process.

  15. Martin says:


    The analogy doesn’t work because it assumes Dave is known/familiar to the person you are tyring to convince. If this person knew Dave, DNA sampling would not be necessary. Simply seeing Dave’s corpse would suffice. It suggests that you cannot produce the corpse.

    What your analogy sets up is a scenario whereby YOU have sole access to Dave’s corpse, YOU sample and show the DNA, and everyone else just has to take your word for it.

    Any reasonably skeptical person wouldn’t swallow that pill. Even if you were to produce a corpse, you couldn’t prove it was Dave’s.

  16. Martin says:


    No argument for a physical being was put forth, therefore you are argument something that isn’t in contention.

    //Therefore the being(s) that finely-tuned our universe could not have been physical – sounds a lot like God to me and would at least qualify as evidence against atheism.//

    The existence, if true, of an intelligence/being responsible for the fine tuning of the cosmos is certainly not an argument against atheism. You haven’t shown how it is even an agument for theism.

  17. Njoroge wa Wahome says:

    I am from Kenya, a very religious place where I would be socially ostracised if I so much as stated that I did not believe in the existence of God. I have not read the entire text of this blog post (sorry, will do so later when I have time) but I have watched two debates between Dr. Turek and Hitchens on YouTube.

    I admire the convincing way Dr. Turek presents his arguments which is, sadly, not the case for Mr. Hitchens.

    Nonetheless, I refuse to take the moral argument Dr. Turek advances. Animals too have a very strict ‘moral code’ so to speak. Does this mean they too have a soul on which such a code is written? and are answerable to a divine being for their actions too?

  18. Njoroge wa Wahome says:

    You say God is spiritual being and not material. Yet in Genesis 1:26 says: “And God said, Let us make man in our image, after our likeness…” How can something or someone who has an ‘image’ and ‘likeness’ not be material?

  19. Ira Mark Egdall says:

    The answer a number of physicists give to cosmic fine tuning is multiple universes. Inflation theory does have supporting observational evidence. And as I understand it, eternal inflation theory suggests ours is only one of a multitude of “island universes.” Current string theory — although still speculation — has an enormous number of possible solutions, also suggesting multiple universes.
    So perhaps our universe is just one of many. And it just happens to have the right fine-tuning for galaxies, stars, planets, and eventually life (on at least one planet). So no “intelligent designer” is necessary under this scenario.
    Or maybe we just don’t yet understand the physics and futures science will show that what appears to be fine-tuning is actually not.


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