Thursday, June 4, 2009

Can the laws of physics evolve?

A friend writes to say that in "The unique universe" (PhysicsWorld.com, 2 June 2009), Toronto-based cosmologist Lee Smolin attempts to develop a different view of time that allows him the laws of physics tp evolve in time. My friend wonders, "Presumably this is an alternative way of addressing the design challenge of fine tuning?"

Here's the essay's At a Glance:

Against the timeless multiverse

- Many cosmologists today believe that we live in a timeless multiverse - a universe where ours is just one of an ensemble of universes, and where time does not exist

- The timeless multiverse, however, presents a lot of problems. Our laws of physics are no longer determinable from experiment and it is unclear what the connection is between fundamental and effective laws

- Furthermore, theories that do not posit time to be a fundamental property fail to reproduce the space-time that we are familiar with

- Many of these puzzles can be avoided if we adopt a different set of principles that postulates that there is only one universe and that time is a fundamental property of nature. This scenario also opens the way to the possibility that the laws of physics evolve in time.
Well, some people go to a lot of trouble to evade the implications of fine tuning of the universe (= design).

Here is what I wrote about Lee Smolin's work in By Design or by Chance?:
New Universes Sprout Only in Black Holes?

Cosmologist Lee Smolin is a bit more conservative than Tegmark. He speculates that new universes might erupt—but not just anywhere that a particle goes one way rather than the other. Perhaps only in the middles of cosmic black holes. The new universes are disconnected from our universe, because the laws of physics break down in black holes. That is why we don’t know about them.

Smolin believes that the eruption of new universes in black holes follows the principles of Darwinism (natural selection). He explains:

"It seemed to me that the only principle powerful enough to explain the high degree of organization of our universe—compared to a universe with the particles and forces chosen randomly—was natural selection itself. The question then became: Could there be any mechanism by which natural selection could work on the scale of the whole universe?"

In other words, natural selection (the outcome of law acting on chance), lurking in a black hole, organizes a complex universe, excruciatingly fine-tuned for life. Smolin does not claim that the black hole spouts millions of them. Alternatively, he is attracted to the idea that the universe organizes itself:

"I believe more in the general idea that there must be mechanisms of self-organization involved in the selection of the parameters of the laws of nature than I do in this particular mechanism, which is only the first one I was able to invent. "

All these universes popping up in the clouds in our coffee, in the torment of a black hole, in the futility of an escaped balloon—their existence guarantees that our universe is a product of chance. If only they would exist . . . if only they would exist . . . (pp. 34-35)
Here are some more fine tuning stories:

Astronomer vs. pop science TV

Materialism strikes back: We create the universe, not God

The universe has hallmarks of desgn: And what can anyone do about it?

Like clouds in our coffee, all these other universes

Major media, imagining themselves sober, think there are many universes, not just double vision

The Big Bang exploded; seriously, is there room for reasonable skepticism about the Big Bang?

Could God live in an infinite sea of universes? It depends.

Will the cosmic multiverse landscape ensure the triumph of intelligent design?

Now, remind me again why we need multiverse theory in the first place?

Multiverse theory: Replacing the big fix with the sure thing?