2006 : WHAT IS YOUR DANGEROUS IDEA?

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Felix Bloch Professor in Theoretical Physics, Stanford; Author, The Cosmic Landscape; The Black Hole Wars
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According to some people, the "Landscape" idea will eventually ensure that the forces of intelligent design (and other unscientific religious ideas) will triumph over true science. From one of my most distinguished colleagues:

From a political, cultural point of view, it's not that these arguments are religious but that they denude us from our historical strength in opposing religion.

Others have expressed the fear that my ideas, and those of my friends, will lead to the end of science (methinks they overestimate me). One physicist calls it "millennial madness."

And from another quarter, Christoph Schönborn, Cardinal Archbishop of Vienna has accused me of "an abdication of human intelligence."

As you may have guessed the idea in question is the Anthropic Principle: a principle that seeks to explain the laws of physics, and the constants of nature, by saying, "If they (the laws of physics) were different, intelligent life would not exist to ask why laws of nature are what they are."

On the face of it, the Anthropic Principle is far too silly to be dangerous. It sounds no more sensible than explaining the evolution of the eye by saying that unless the eye evolved, there would be no one to read this page. But the A.P. is really shorthand for a rich set of ideas that are beginning to influence and even dominate the thinking of almost all serious theoretical physicists and cosmologists.

Let me strip the idea down to its essentials. Without all the philosophical baggage, what it says is straightforward: The universe is vastly bigger than the portion that we can see; and, on a very large scale it is as varied as possible. In other words, rather than being a homogeneous, mono-colored blanket, it is a crazy-quilt patchwork of different environments. This is not an idle speculation. There is a growing body of empirical evidence confirming the inflationary theory of cosmology, which underlies the hugeness and hypothetical diversity of the universe.

Meanwhile string theorists, much to the regret of many of them, are discovering that the number of possible environments described by their equations is far beyond millions or billions. This enormous space of possibilities, whose multiplicity may exceed ten to the 500 power, is called the Landscape. If these things prove to be true, then some features of the laws of physics (maybe most) will be local environmental facts rather than written-in-stone laws: laws that could not be otherwise. The explanation of some numerical coincidences will necessarily be that most of the multiverse is uninhabitable, but in some very tiny fraction conditions are fine-tuned enough for intelligent life to form.

That's the dangerous idea and it is spreading like a cancer.

Why is it that so many physicists find these ideas alarming? Well, they do threaten physicists' fondest hope, the hope that some extraordinarily beautiful mathematical principle will be discovered: a principle that would completely and uniquely explain every detail of the laws of particle physics (and therefore nuclear, atomic, and chemical physics). The enormous Landscape of Possibilities inherent in our best theory seems to dash that hope.

What further worries many physicists is that the Landscape may be so rich that almost anything can be found: any combination of physical constants, particle masses, etc. This, they fear, would eliminate the predictive power of physics. Environmental facts are nothing more than environmental facts. They worry that if everything is possible, there will be no way to falsify the theory — or, more to the point, no way to confirm it. Is the danger real? We shall see.

Another danger that some of my colleagues perceive, is that if we "senior physicists" allow ourselves to be seduced by the Anthropic Principle, young physicists will give up looking for the "true" reason for things, the beautiful mathematical principle. My guess is that if the young generation of scientists is really that spineless, then science is doomed anyway. But as we know, the ambition of all young scientists is to make fools of their elders.

And why does the Cardinal Archbishop Schönborn find the Landscape and the Multiverse so dangerous. I will let him explain it himself:

Now, at the beginning of the 21st century, faced with scientific claims like neo-Darwinism and the multiverse hypothesis in cosmology invented to avoid the overwhelming evidence for purpose and design found in modern science, the Catholic Church will again defend human nature by proclaiming that the immanent design evident in nature is real. Scientific theories that try to explain away the appearance of design as the result of 'chance and necessity' are not scientific at all, but, as John Paul put it, an abdication of human intelligence.

Abdication of human intelligence? No, it's called science.