Copernican or Anthropic?

The Polish astronomer Copernicus (1473-1543) is generally credited with establishing that the center of the solar system is the sun and not the Earth.* Subsequent astronomical research has shown that our sun is not at the center of our galaxy nor is our galaxy at the center of the universe. Add to this the modern recognition that the universe contains on the order of 100 billion trillion stars, and the result is the idea that the Earth is nothing special, location-wise, ontologically, or in its characteristics. This notion, popularized by the late astronomer Carl Sagan, is often referred to as the "Copernican Principle." This is a misnomer, of course, as Copernicus didn't share Sagan's religious views, and didn't overstate the physical evidence to support an unwarranted metaphysical claim. A better name for this idea--still popular among moderns (especially sci-fi fans who, like Sagan, consider it reasonable to think that the Cosmos is replete with planets hosting intelligent life forms)--is the "principle of mediocrity."

Today, however, anyone affirming the principle of mediocrity would be guilty--as was Sagan in his later years--of committing the fallacy of supressed evidence. During Sagan's lifetime and since, overwhelming evidence contrary to Sagan's view has been accumulating. General relativity has by now become the most rigorously tested theory in all of physics, and its logical product--big bang cosmology--has proved fatal for Sagan's view that "The Cosmos is all there is, or ever was, or ever will be." Moreover, astronomers, chemists, and physicists are continually identifying characteristics of the universe that are extremely fine-tuned to provide for human life. The current understanding--the anthropic principle--has turned the "Copernican" Principle on its head, and we now know (for example) that our sun's place within the galaxy and our galaxy's place within the galaxy cluster are (while not central) exactly what they need to be for life on Earth to be possible. According to astrophysicist Paul Davies...

There is for me powerful evidence that there is something going on behind it all… It seems as though somebody has fine-tuned nature’s numbers to make the Universe… The impression of design is overwhelming.

Stephen Hawking likewise expressed the latest understanding,

It would be very difficult to explain why the universe should have begun in just this way, except as the act of a God who intended to create beings like us.

In days to come, I'll be sharing just a few of the 93+ fine-tuned characteristics of the universe itself (fundamental fine-tuning)and the 154+ characteristics of the galaxy, solar system, and Earth (environmental fine-tuning) that fall within extremely narrow (life-permitting) ranges. If you want to learn more about this yourself, I recommend Hugh Ross' The Creator and the Cosmos, The Privileged Planet by Guillermo Gonzalez and Jay Richards, and the Reasons To Believe website (where updated lists of these characteristics can be found).




*Copernicus' immediate successors, Bruno and Galileo, played important roles in getting this understanding out. Moreover, there is some indication that even Ptolemy recognized ours as a heliocentric system. His system of concentric rings (that is to us moderns Ptolemy's legacy and which brands him as geocentric) may have been his best bet for predicting the locations of the planets given the rather undeveloped geometry of his day.

(I originally posted a version of this post on 16 March 2007.)