In my previous post, I highlighted three common atheistic objections to to the cosmological fine-tuning argument. In that post, I made no attempt to answer these objections. My aim was simply to show that the objections were weak and inconclusive.
Let’s go back to the original three objections:
1. If the universe was designed to support life, then why does it have to be so BIG, and why is it nearly everywhere hostile to life? Why are there so many stars, and why are so few orbited by life-bearing planets? (Let’s call this the size problem.)
2. If the universe was designed to support life, then why does it have to be so OLD, and why was it devoid of life throughout most of its history? For instance, why did life on Earth only appear after 70% of the cosmos’s 13.7-billion-year history had already elapsed? And Why did human beings (genus Homo) only appear after 99.98% of the cosmos’s 13.7-billion-year history had already elapsed? (Let’s call this the age problem.)
3. If the universe was designed to support life, then why does Nature have to be so CRUEL? Why did so many animals have to die – and why did so many species of animals have to go extinct (99% is the commonly quoted figure), in order to generate the world as we see it today? What a waste! And what about predation, parasitism, and animals that engage in practices such as serial murder and infant cannibalism? (Let’s call this the death and suffering problem.)
In today’s post, I’m going to try to provide some positive answers to the first two questions: the size problem and the age problem.
1. An answer to the size problem
(a) The main reason why the universe is as big as it currently is that in the first place, the universe had to contain sufficient matter to form galaxies and stars, without which life would not have appeared; and in the second place, the density of matter in the cosmos is incredibly fine-tuned, due to the fine-tuning of gravity. To appreciate this point, let’s go back to the earliest time in the history of the cosmos that we can meaningfully talk about: the Planck time, when the universe was 10^-43 seconds old. If the density of matter at the Planck time had differed from the critical density by as little as one part in 10^60, the universe would have either exploded so rapidly that galaxies wouldn’t have formed, or collapsed so quickly that life would never have appeared. In practical terms: if our universe, which contains 10^80 protons and neutrons, had even one more grain of sand in it – or one grain less – we wouldn’t be here.
Fine-tuning expert Dr. Robin Collins elucidates these points in an article entitled, The Teleological Argument: An Exploration of the Fine-Tuning of the Universe (in The Blackwell Companion to Natural Theology, edited William Lane Craig and J. P. Moreland. Copyright 2009 Blackwell Publishing Ltd. ISBN: 978-1-405-17657-6). On page 215 he writes:
” There is … a fine-tuning of gravity … relative to the density of mass-energy in the early universe and other factors determining the expansion rate of the Big Bang – such as the value of the Hubble constant and the value of the cosmological constant. Holding these other parameters constant, if the strength of gravity were smaller or larger by an estimated one part in 10^60 of its current value, the universe would have either exploded too quickly for galaxies and stars to form, or collapsed back on itself too quickly for life to evolve.”
In the footnote, Collins clarifies the connection between the fine-tuning of gravity and the density of matter in the cosmos:
Footnote 10. This latter fine-tuning of the strength of gravity is typically expressed as the claim that the density of matter at the Planck time (the time at which we have any confidence in the theory of Big Bang dynamics) must have been tuned to one part in 10^60 of the so-called critical density (e.g. Davies 1982, p. 89). Since the critical density is inversely proportional to the strength of gravity (Davies 1982, p. 88, eqn. 4.15), the fine-tuning of the matter density can easily be shown to be equivalent to the aforementioned claim about the tuning of the strength of gravity. (Bold emphases mine – VJT.)
(b) The theory of cosmic inflation doesn’t solve the problem of the fine-tuning of gravity either. Physicist Dr. Robert Sheldon succinctly exposed the shortcomings of cosmic inflation in a personal email communication to me:
Take inflation, which was supposed to make it as easy as falling off a log to get this precise balance between too much and too little mass. Forget the fact that the existence of the inflaton [the hypothetical field thought to be responsible for cosmic inflation – VJT] has never been observed, or even hinted at except for this Big Bang problem, making it an ad hoc theory par excellence, and forget the fact that we are now 3 or 4 versions later, after earlier versions proved to not work as advertised, the actual fact is that the fine tuning of inflation requires better than 10^80, which makes one wonder whether the cure is worse than the disease.
So no, the problem hasn’t been solved, if we interpret the problem as the fine-tuning necessary to get our particular universe. (Bold emphasis mine – VJT.)
(c) The fact that the universe is mostly inhospitable to life has a simple explanation: a universe that was life-friendly everywhere would actually be less elegant, mathematically speaking, and hence less likely to be made by an Intelligent Designer. As Dr. Robin Collins has argued, the laws of our universe are extremely elegant, from a mathematical perspective. (See also my post, Beauty and the multiverse.) If there is an Intelligent Designer, He presumably favors mathematical elegance. Accordingly, the most likely reason why most of the universe is inhospitable to life is the recipe for making a big universe with a few tiny islands of life is mathematically simpler and morer elegant than the the recipe for making a universe with life everywhere, given the laws of Nature as we know them.
(d) Atheists might object that a Cosmic Designer could make a universe which was small and everywhere life-friendly with a different set of laws. If they want to argue that way, that’s fine, but as I argued in my previous post, the onus is on atheists to show us exactly how these hypothetical laws would differ from those in our universe, and how these laws would produce a life-friendly universe.
2. An answer to the age problem
(a) One reason why we need an old universe is that billions of years were required for Population I stars (such as our sun) to evolve. These stars are more likely to harbor planets such as our Earth, because they contain lots of “metals” (astronomer-speak for elements heavier than helium), produced by the supernovae of the previous generation of Population II stars. According to currently accepted models of Big Bang nucleosynthesis, this whole process was absolutely vital, because the Big Bang doesn’t make enough “metals”, including those necessary for life: carbon, nitrogen, oxygen, phosphorus and so on.
(b) Dr. Robert Sheldon, in a personal email communication, suggests another reason why the universe needs to be very old. According to Einstein, space and time are interchangeable. So by symmetry, a universe which is large enough to contain 100 billion galaxies (each having about 100 billion stars), in addition to lots of quasars, must have also had a long history.
In short, if you want a massive universe, with lots of galaxies and stars, then it has to be large, and if it’s large, then it has to be old.
I’ll address the death and suffering problem in a forthcoming post.