The psalmist proclaims, "The heavens declare the glory of God; the skies proclaim the work of his hands." (Psalm 19:1) From ancient times to the present, people have looked at the natural world, have marveled at it, and have seen in it the handiwork of God. And from the time of the ancient Greeks onward, the evident order of the natural world has been the basis for an argument to the existence of God, an argument known as the "argument from design".

The most common form of this argument in the past has been one that starts with biological structures such as the hand or the human eye and asks how such extraordinary structures, both in complexity and in function, could have arisen by chance. However, with Charles Darwin and the advent of evolutionary theory there arose a possible way of accounting for the emergence of such structures, a way which makes no appeal to intentional design, relying only on the blind processes of random mutation and natural selection. That change does take place in this way is now quite evident, and evolutionary theory has become an important part of a contemporary understanding of biology. This, however, does not entail the conclusion that blind (unguided) physical processes can alone be adequate to account for either the emergence or the development of life. If one assumes that God does not exist (and if one discounts all forms of animism and polytheism), then one is left with nothing but blind physical processes, and, given that we are here, it becomes a foregone conclusion that such processes must have been adequate.

It may come as a surprise to many that there are indeed good reasons for doubting the sufficiency of such processes,¹ but this talk will not deal with that question. Rather it will address the question as to whether the content of the laws of physics themselves constitute evidence for a designer. The issue here can be formulated as a question. Do the laws of physics themselves manifest an apparent fine tuning without which life would not be possible? At present, this question must be formulated in terms of what are called "basic physical constants," such things are the strengths of the four basic forces (electromagnetism, the weak and strong nuclear forces, and gravity), the mass and spin of various fundamental particles, and the speed of light. The question, therefore, is, had the physical constants been slightly different from what they are, would anything like life have been possible? Obviously if those constants had been different, we would not be here, but the issue is whether anything like life would have been possible.

The surprising answer to that question is that the laws of physics do seem fine-tuned for the possibility of life. Put another way, there exists amongst the basic physical constants a delicate balance without which nothing like life would have been possible. This is not just the conclusion of theists, of those who would be delighted to find that this is the case; it is a conclusion shared by most atheists who have wrestled with the question. See, for instance a recent book by the astrophysicist Martin Rees, Before the Beginning: Our Universe and Others.² He is by no means a theist but is convinced that the apparent delicate balance of natural law is real.

Does granting that there is an apparent fine tuning of natural law necessitate that one believe there is a cosmic designer? No, it does not. The most common response amongst atheists is to speculate that there are a vast number of universes amongst which the basic physical constants vary vary in a random or indeterministic way. The claim then is that the fine tuning which we observe simply reflects the truism that intelligent life can only exist where such fine tuning exists. I will say more about this explanation in the next talk and also address courrent speculation as to what brought about the origin of the universe, but the aim of this talk is to advance the thesis that the laws of physics do indeed exhibit an extraordinary fine tuning, a fine tuning which makes life possible. Astrophysicist Paul Davies has expressed it as follows:

I will give two examples of the evidence in question. A number of others could be given.

1. THE WEAK NUCLEAR FORCE AND SUPERNOVAE

According to the big bang theory, the only elements to form in the primordial heat of the big bang were hydrogen and helium (with very small traces of lithium and berylium). Life requires complex structure and hydrogen and helium do not provide a basis for such complexity of structure.⁴ Hence the eventual appearance of life required first the emergence of the heavier elements. These, are formed in the center of stars through nuclear fusion. Most of the "life" of a star consists of that long period in which hydrogen is fused into helium. Eventually enough of the helium gets used up that the heat generated thereby is unable to counter the gravitational attraction of the stars mass and the star begins to shrink in volume. Such compaction itself generates more heat, that heat rising until temperatures are achieved at which the helium can fuse into heavier elements. As reserves of helium deplete further contraction occurs enabling the formation of successively heavier elements.

However, for these heavier elements to become the basis for life they need to be released from the center of the stars in which they form. For stars the size of our sun, these heavier elements never escape from the star. Such stars eventually use up their nuclear fuel and collapse into highly dense stars known as white dwarfs, stars which gradually cool as would a cinder turning cold. The heavier elements within such stars are trapped. If stars are large enough the gravitation force will result in a black hole. That heavier elements can get released from stars is due to what are known as supernovae, a catastrophic implosion of a stars which in turn triggers a spectacular explosion from the heat generated by the implosion. The inner portion of the star collapses into what becomes a neutron star and the outer portion is blown away by the massive energy generated.
It is with regard to supernovae that a "fine tuning" of the weak force becomes relevant
The favored explanation as to what makes the explosion is that the imploding core of the stars produces an enormous number of neutrinos. These are massless, or nearly so, and interact very little with ordinary matter-they can easily pass through the Earth without touching it. However, the densities of the imploding core are so great that the neutrinos exert sufficient pressure to blow away the outer portion of the star. The weak force is crucial for it is through weak interactions precipitated by the implosion that the neutrinos are formed. Calculations show that "If the weak interaction were much weaker, the neutrinos would not be able to exert enough pressure on the outer envelope of the star to cause the supernova explosion. On the other hand, if it were much stronger, the neutrinos would be trapped inside the core, and rendered impotent."⁵ With regard to a weaker weak force, Leslie, citing Rees as a source, says, "While calculations are hard, it seems a safe bet that weakening the weak force by a factor of ten would have led to a universe consisting mainly of helium and in which the life-producing explosions could not occur."⁶ Thus life depends on the weak nuclear force falling within this range.⁷

2. HELIUM, BERYLLIUM AND CARBON RESONANCES

All forms of life with which we are familiar are carbon-based. Need it be so? Some have speculated that silicon might be a possible alternative. Silicon is located in the same column of the periodic table as carbon and in the row below it. Both have a valence of four, meaning that they each have four electrons available to enter into chemical bonds. Nonetheless, silicon has serious disadvantages. Carbon can form double bonds with other elements, i.e. share two electrons with another atom; silicon forms only single bonds. Thus carbon dioxide is a stable and exists as a gas"enabling it, among other things, through photosynthesis, to be the ultimate source of carbon in all living things. By contrast, silicon dioxide can form only single bonds, leaving two electrons free to form other bonds and likewise leaving the oxygen atoms free to bond. The result is that it tends, when bonding to itself, to form a crystal, namely quartz. Thus silicon becomes overly stable. At the same time it can be not stable enough, for silicon can actually form up to six bonds, making more complex silicon compounds less stable than carbon compounds, where the bonds never exceed four. Also the C"C bond is more stable than the Si"Si bond. It is crucial to DNA that, although it is very long, it is nonetheless normally very stable. It is also significant that the various bonds into which carbon enters are similar in the energy required to form them and are also fairly evenly divided between being endothermic and exothermic (absorb energy vs. release energy). Both of these facts result in there being a great number of chemical processes involving carbon which can take place with relative spontaneity. Silicon is not nearly so well suited. Finally, "Since carbon forms a wider variety of compounds than any other element besides hydrogen, this means that more information can be stored in carbon compounds than in those of any other element. Since life is self-reproduction of information, carbon compounds are uniquely fitted to serve as the basis of life."⁸ Much more could be said, but it should be evident that even if silicon-based life were possible"which is dubious, it appears to be a decidedly less attractive alternative.

Saying this about carbon is really a lead-in to a point raised by Fred Hoyle about the formation of carbon in stars. He suggested (and it was later shown) that carbon is able to form readily in stars of the right temperature because of a resonance between carbon, beryllium, and helium. Just as electrons may exist at various distinct energy levels, so different kinds of nuclei exhibit distinct energy levels at which they may exist. Now, when two nuclei fuse, the efficiency of the reaction is greatly enhanced if the intrinsic energy level of the contributing nuclei together with the kinetic energy equals or just exceeds a possible energy level for the resulting nucleus. When this happens the interaction is said to be resonant . Hoyle realized that for carbon to form successfully there would have to be resonance. Fortunately, this does occur in stars in the formation of carbon. The process involves two helium nuclei fusing to form beryllium-8, which although not stable, exists "anomalously long compared to the He4 + He4 collision time,"⁹ due to a resonance between He4 and Be8. The Be8 exists long enough for a significant rate of collisions of it with another He4 nucleus. Remarkably, C12 also has a resonance with both He4 and Be8 in this interaction. As a consequence, a significant amount of carbon is produced in spite of what appeared initially to be an implausible pathway for its production. Fortunately for us, the further fusion of carbon with another helium into oxygen does not resonate.

The presence or absence of resonances here could in theory be accounted for in terms of the strong nuclear force, the electromagnetic force, and the masses of the sub-atomic particles involved but, with atoms of this size, the complexity of it becomes overwhelming. Nonetheless, Hoyle suggests that perhaps an increase in the strong force by but 1% might cause almost all carbon to have formed into oxygen,¹¹ and Rosental suggests that an increase in it of 10% would result in little carbon being able to form, the fusion process getting stuck at helium.¹² And if it were a bit larger than this, Carr and Rees indicate that "nuclei of almost unlimited size" would form.¹³

Part of what is interesting about the aforementioned resonances is that it is not the kind of coincidence which one would expect some overarching theory of the universe to entail. It certainly may be so entailed, but there is no a priori reason to expect it. Resonance is not the rule; and apart from the fact that we are here, there is no reason to expect that the resonances of the above reactions should be as they are.

Again, there are many other examples of apparent fine tuning which could have been mentioned, but the two examples illustrate the sort of arguments As mentioned above, the apparent fine tuning of the laws of physics does not itself entail that there is a cosmic designer,¹⁴ but it does lend significant support to that claim that this world is the handiwork of God.

1. See for instance, Michael Behe's Darwin's Black Box (New York: Simon & Schuster [Free Press], 1996)) or Dean Overman's A Case Against Accident and Self-Organization (Rowman & Littlefield). (back)
2. Reese, Martin, Before the Beginning: Our Universe and Others (Reading, MA: Addison Wesley [Helix Books, Perseus Books], 1997). See especially pp. 231-239. .(back)
3. P[aul] C. W. Davies, The Accidental Universe (Cambridge: Cambridge Univ. Press, 1982), vii. (back)
4. Helium is inert and hence does not bind with any other elements, and lacking sigificant quantities of other elements, hydrogen atoms will simply form into pairs of hydrogen atoms. (back)
5. Ibid., 68. For a more mathematical account of this see Barrow and Tipler, The Anthropic Cosmological Principle, 309-310, or see the article by B. J. Carr and M. J. Rees, "The Anthropic Principle and the Structure of the Physical World," Nature 278, 12 (1979): 605-612. (back)
6. Leslie, Universes, 35. He cites Martin J. Rees in The Constants of Physics: Proceeding Meeting by A Royal Society Discussion Meeting. Held on 25 and 26 May 1983. , eds. William Hunter McCrea and Martin J. Rees, London: Philosophical Transactions of the Royal Society, A310 (1983): 209-363. (back)
7. Small amounts of some of the lighter elements, e.g. up through oxygen, can escape from certain classes of stars via stellar winds, but this is minute compared to what comes from supernovae (back)
8. Barrow and Tipler, The Anthropic Cosmological Principle, 547. Again, they provide references to a number of other sources. (back)
9. Ibid., 252. (back)
10. Ibid., 253. (back)
11. Fred Hoyle, Astrophysical Journal , supplementary 107 (1957): 516. (back)
12. I. L. Rozental, Structure of the Universe and Fundamental Constants (Moscow: 1981), 8. Cited in Leslie, Universes, 35. (back)
13. M. J. Rees, in The Constants of Physics, 611. (back)
14. The usual atheistic response these days is to suggest that there are a vast number of universes or big bangs amongst which the values of the basic physical constants vary. That the physical constants which we observe seem fine tuned so as to make life possible is explained simply by virtue of the truism that any location (or universe) where creatures like ourselves could be pondering this fact must be in a place which is capable of sustaining their existence. If the existence of intelligent beings requires that the values of the physical constants fall within very narrow ranges, then such beings should not be surprised that they find themselves in such a location. But it must be noted that the strength of this kind of response (as opposed to suggesting that the fine tuning is evidence of a designer, i.e. God) depends on the multiple-universe speculation and on the idea that the constants vary across these universes. Such speculation, however, is not driven by any evidence that such universes exist other than the apparent fine tuning itself. (An alternative way of getting a multiple-universe type explanation is to embrace the many-World interpretation of quantum mechanics, but this has major difficulties which must be addressed on another occasion.) (back)