Messier 92 in the Hercules constellation.
My friend Lawrence Rifkin MD. published a wonderful piece in Scientific American, “The Logic and Beauty of Cosmological Natural Selection.” Rifkin argues that “The hypothesis [of] cosmological natural selection, and its power, beauty, and logic provide what may be the best scientific explanation for the existence of complexity and life in the universe.” CNS has been most extensively formulated by the physicist Lee Smolin in his 1992 book The Life of the Cosmos. Here is a basic description:
Throughout the universe, stars that collapse into black holes squeeze down to an unimaginably extreme density. Under those extreme conditions, as a result of quantum phenomenon, the black hole explodes in a big bang and expands into its own new baby universe, separate from the original. The point where time ends inside a black hole is where time begins in the big bang of a new universe. Smolin proposes that the extreme conditions inside a collapsed black hole result in small random variations of the fundamental physical forces and parameters in the baby universe. So each of the new baby universes has slightly different physical forces and parameters from its parent. This introduces variation.
Given these “inherited characteristics, universes with star-friendly parameters will produce more stars and reproduce at a greater rate than those universes with star-unfriendly parameters. So the parameters we see today are the way they are because, after accumulating bit by bit through generations of universes, the inherited parameters are good at producing stars and reproducing.” Of course, the existence of stars is crucial because the molecular material contained in stars is a prerequisite of life.
One of the advantages of CNS is that it directly addresses the so-called “fine-tuning problem”—why the laws and parameters of nature are remarkably conducive to life. It answers that the laws of our universe “are the way they are because of non-random naturalistic cumulative inherited change through reproductive success over time.” CNS also explains the complexity and the apparent design of our universe without positing gods, analogous to how natural selection explains the complexity and apparent design of our biology.
Critics might argue that there is no evidence for CNS, but Rifkin points out that there is no direct evidence for other scientific alternatives that would explain the existence of our universe like quantum fluctuations, multiverses, cyclic universes, or brane cosmology. And CNS has the advantage of explaining the fine-tuning problem better than the alternatives, which is why Rifkin thinks CNS will eventually be vindicated.
Furthermore, CNS has profound implications for the question of life’s meaning. “In a world of branching universes conducive to life, ultimate cosmic doom may be avoided, keeping alive the possibility of eternity—not for us as individuals, or for Homo sapiens, but for the existence of life at large in the cosmos.” So the future of the cosmos is open, still to be determined—surely a more hopeful message that inevitable cosmic death. Yet this does not imply that we were meant to be here, that the universe cares about us, or that any teleology is at work—Rifkin definitely rejects any god of the gaps.
In the end, CNS, like any scientific idea, stands or falls on the evidence. “If evidence proves any one of the cosmological alternatives—or an entirely new idea altogether—we will embrace reality, no matter where it leads, and be struck with awe at our ability to discover the grandest of cosmological truths and our place in the universe.”
I am unqualified to adjudicate between various cosmological theories but CNS appears to be a robust theory that is consistent with perhaps the greatest idea of all time—the idea that everything, from the cell to the cosmos, evolves over time.
Moreover, CNS provides a straightforward solution to the so-called fine-tuning problem. I have no doubt that there is a naturalistic solution to this problem—assuming we can even be sure the cosmos is fine-tuned. (Some theorists suggest we don’t know enough to say for sure.) But if our universe is fine-tuned, then naturalistic solutions will explain it. Scientific solutions will close this gap in our knowledge like they have previously closed so many others. This is after all one of the main reasons why so few philosophers are non-naturalists. Science works.
Still, people will find their gods hiding in the gaps of quantum or cosmological theories, or in dark matter or energy. If you are determined to believe something it is hard to change your mind. But defenders of the gods fight a rearguard action—scientific knowledge is relentless—and these hidden gods are nothing like the traditional ones. Traditional gods are dead.
And as science closes the gaps in our knowledge the gods will recede further and further into the recesses of infinite space and time until they vanish altogether, slowly blown away, not by cosmic winds, but by ever-encroaching thought.
This essay was originally published on this blog on June 20, 2014.