2008 : WHAT HAVE YOU CHANGED YOUR MIND ABOUT? WHY?

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Theoretical physicist; cosmologist; astro-biologist; co-Director of BEYOND, Arizona State University; principle investigator, Center for the Convergence of Physical Sciences and Cancer Biology; author, The Eerie Silence and The Cosmic Jackpot
I used to be a committed Platonist.

For most of my career, I believed that the bedrock of physical reality lay with the laws of physics — magnificent, immutable, transcendent, universal, infinitely-precise mathematical relationships that rule the universe with as sure a hand as that of any god. And I had orthdoxy on my side, for most of my physicist colleagues also believe that these perfect laws are the levitating superturtle that holds up the mighty edifice we call nature, as disclosed through science. About three years ago, however, it dawned on me that such laws are an extraordinary and unjustified idealization.

How can we be sure that the laws are infinitely precise? How do we know they are immutable, and apply without the slightest change from the beginning to the end of time? Furthermore, the laws themselves remain unexplained. Where do they come from? Why do they have the form that they do? Indeed, why do they exist at all? And if there are many possible such laws, then, as Stephen Hawking has expressed it, what is it that "breathes fire" into a particular set of laws and makes a universe for them to govern?

So I did a U turn and embraced the notion of laws as emergent with the universe rather than stamped on it from without like a maker's mark. The "inherent" laws I now espouse are not absolute and perfect, but are instrinsically fuzzy and flexible, although for almost all practical purposes we don't notice the tiny flaws.

Why did I change my mind? I am not content to merely accept the laws of physics as a brute fact. Rather, I want to explain the laws, or at least explain the form they have, as part of the scientific enterprise. One of the oddities about the laws is the well known fact that they are weirdly well-suited to the emergence of life in the universe. Had they been slightly different, chances are there would be no sentient beings around to discover them.

The fashionable explanation for this — that there is a multiplicity of laws in a multiplicity of parallel universes, with each set of laws fixed and perfect within its host universe — is a nice try, but still leaves a lot unexplained. And simply saying that the laws "just are" seems no better than declaring "God made them that way."

The orthodox view of perfect physical laws is a thinly-veiled vestige of monothesim, the reigning world view that prevailed at the birth of modern science. If we want to explain the laws, however, we have to abandon the theological legacy that the laws are fixed and absolute, and replace them with the notion that the states of the world and the laws that link them form a dynamic interdependent unity.