Saturday, March 09, 2013

George Dvorsky on the Anthropic Principle at io9

Over at io9, George Dvorsky has posted an interesting and well-done article on the anthropic principle. This topic is of special interest to me because it's one of the issues that bothers me about Buddhism, integral theory, and various other theories that posit a universe with consciousness as an essential element of its existence.

Theories of emergence make a lot more sense to me without the need for panpsychism as an explanatory feature for the existence of consciousness.

How does the Anthropic Principle change the meaning of the universe?

George Dvorsky
March 8, 2013

One of the more extraordinary things about the universe is that it has produced beings who can observe it — namely, us. Its laws and constants are so precise that, if they were even slightly modified, no human would be here to see it. Many cosmologists and philosophers have wondered if we should read anything into all this preciseness: Are the finely-tuned physical laws that surround us mere coincidence, or does it imply that we are somehow meant to be here? That's where the Anthropic Principle comes into play.

The Anthropic Principle (AP) is that hazy grey area where philosophy meets science. And in fact, many scientists loathe it for this very reason. It's untestable, they argue, and tautological — a skewed form of reasoning in which the principle is basically being used to prove itself.

And indeed, the AP does seem like a strange concept at first. It essentially states that we will only find ourselves in a universe that's capable of giving rise to us. Put another way, observations of the universe must be compatible with the conscious life that observes it.

It's a principle that makes perfect sense — and for some, no sense at all. But like so many things in science and philosophy, the devil is in the details.

The AP forces us to take a giant step back and evaluate the conditions of the universe in consideration of our presence within it. For scientists, it's a kind of ‘40 foot perspective' that can help illuminate — and even possibly explain — some of the more surprising aspects of cosmology. And at the very least, it serves as a constant reality check to remind us that we will always be subject to observational selectional effects; no matter where we go, we will always be there.

A good thought experiment in this regard comes from the Canadian philosopher John Leslie. In his book, Universes, he asks us to imagine a man facing a firing squad of fifty expert marksman. After aiming and firing, the executioners miss their mark.

Now, there are two ways in which we can evaluate this surprising outcome. We can either shrug our shoulders and point to the obvious, that they they simply missed. Or we can come up with some explanations as to why they all missed. This latter point is very much at the heart of anthropic reasoning.


The AP has been around for quite some time, though it only really took on its modern form in the last forty years.

Early efforts to come to grips with observational effects were expressed in Hume's Dialogues Concerning Natural Religion, and Kant's ideas about how our experience of the world is formulated by our sensory and intellectual faculties. Back in the 1920s, James Jeans observed that, "the physical conditions under which life is possible form only a tiny fraction of the range of physical conditions which prevail in the universe as a whole." Likewise, his contemporary, Arthur Eddington, speculated about "selective subjectivism," the idea that the laws of nature are indirectly imposed by the human mind, which in turn determines (and constrains) what we know about the universe.

More recently, some scientists have used it to explain the series of bizarre "large-number coincidences" in physics and cosmology. These are the surprisingly large order-of-magnitude connections that exist between (apparently) unrelated physical constants and cosmological parameters.

For example, the electromagnetic force is 39 orders of magnitude stronger than gravity. If it was any closer in strength, stars would have collapsed long before life could emerge. Or, the universe's vacuum energy density is about 120 orders of magnitude lower than some theoretical estimates, which, if any higher, would have blown the universe apart. And the neutron is heavier than the proton — but not so heavy that neutrons cannot be bound in nuclei where conservation of energy prevents the neutrons from decaying. Without neutrons, we wouldn't have the heavier elements needed for building complex life. There are many other examples, each one pointing to extreme specificity.

In 1961, Robert. H. Dickie used a prototypical version of the AP to explain away these coincidences, saying that physicists were reading too much into it. These large numbers, he argued, are a necessary coincidence (or prerequisite) for the presence of intelligent beings. If these parameters were not so, life would not have arisen. And in turn, we wouldn't be here to marvel at the ‘surprisingness' of these physical constants and laws.
Read the whole interesting article.
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