Wednesday, February 11, 2009

Lee Smolin's Darwinian Multiverse

Discover Magazine today published an article called "We All Live In Darwin's World." The article claims that Darwin's theory of natural selection is being shown to apply to nearly everything, to include physical cosmological theories. The articles focuses on physicist Lee Smolin's theory of "cosmological natural selection."

Smolin "developed a theory that posits the existence of a vast number of unseen universes, each generated by the collapse of a black hole. The conditions of those collapses bestow each universe with its own set of fundamental parameters, such as the masses of its various subatomic particles. Just as life diversified on Earth, the “multiverse” in Smolin’s theory evolved from simple beginnings into a complex and varied assemblage of universes, each exhibiting a distinctive set of traits."

The article states: "If a wealth of universes with unique parameters exists, Smolin says, then our own case does not seem so special or so unlikely. In fact, cosmological natural selection specifically favors universes—like ours—in which massive stars can form and give rise to new black holes. “By using Darwinian methodology, I was able to get an explanation for the improbable complexity of our universe,” Smolin says."

So, note first that if there is not a multiverse, then our universe seems special and improbably complex. So an atheist like Smolin really needs a multiverse to exist. Note: Valentine's Day is approaching. If you have a friend who is an atheist (and I do have a number of atheist friends) it would be nice to get them a good multiverse theory for a gift.

Smolin's multiverse theory is not universally accepted by physicists. That's not to say his theory is false. Truth and falsity are not functions of peer approval. But one must note, e.g., the work of Tufts University physicist Alexander Vilenkin. See his article "On Cosmic Natural Selection." Vilenkin writes: "Smolin points out that his theory would be falsified if black hole production were shown to increase when the constants of nature are varied from their present values. He has repeatedly challenged the physics community to refute his theory and maintains that, despite seferal attempts, it has not yet been falsified." In Vilenkin's essay he argues "that black hole production can be enhanced by an increase in the value of the cosmological constant, thus falsifying Smolin's conjecture."

How should one study this? One text often cited is Universe or Multiverse?, edited by Bernard Carr. It contains articles by physicists Smolin, Stephen Hawking, and many others - totalling over 500 pages (and $69!!). Here one sees the debate go back and forth over whether multiverse theory is not only true but whether it is even in principle verifiable and "scientific."

From Darwin's finches to multiverse theory? The thought comes to me that, as Feb. 12 is the 200th anniversary of Darwin's birthday (go here to join the celebration), people like Lee Smolin have their party hats on ready to thank Charles Darwin for everything. Perhaps Darwin has given us the long-sought-after "theory of everything?" "Natural selection" is beginning to take on the omni-attributes that have been attributed to God. Natural selection accounts for love, war, economics, art, creativity, religion, God, and the universe ("In the beginning Natural Selection created..."). Soon Natural Selection will explain why physicists need to posit a multiverse, and why they react negatively to the idea of a single universe (for their survival?). We will then see Lee Smolin's behavior fully explained, and then understand why he theorizes as he does. Then we'll get at the deepest question, which is: If Natural Selection explains everything, what causes it? Or, a bit lighter, what caused Darwin? Perhaps some caution should be exercised here.