The phrase “Copernicus principle” was invented to suggest the earth and the life upon it are common, occupying no significant status in the cosmos. Today this viewpoint dominates among scientists.
Later, Brandon Carter coined the term “anthropic principle” when asking why everything is just right at this time and place to support intelligent life capable of studying the universe.
So what conditions are just right? Fred Hoyle’s classic comment summarized what was known at that time, “A common sense interpretation of the facts suggests that a super intellect has monkeyed with physics, as well as with chemistry and biology, and that there are no blind forces worth speaking about in nature.”
In the following years, the evidence has continued to grow. The cover jacket of Caleb Scharf’s 2014 book explains, “recent evidence challenges the Copernican Principle, hinting that we do in fact live in a special place, at a special time, as the product of a chain of unlikely events.” Why then does he and others shrug off the accumulating evidence that both our universe and our planet are very special places fine tuned for intelligent life?
They regard this evidence as merely a posteriori reasoning. This is significant because statistical probability rejects the ability of a posterori reasoning to provide credible conclusions. That is, one can not allow the result after the fact to infuse significance into the process and its result. To illustrate why, statisticians will tell an improbable story.
Imagine that a guy named Tom missed work due to illness. While at home he happened to enter and win a TV contest giving him a free baseball ticket. Now imagine a whole succession of further improbable circumstances culminating in a record-shattering-home-run baseball falling into Tom’s soda drink as he walked back to his stadium seat.
Tom might reason, “the odds against all of these things happening is just too great! There must be special significance behind catching this ball.”
Contrary to Tom’s feelings, he was just lucky. Why? Although catching that ball was improbable, any series of events could have led to this result. Tom can not legitimately attach significance after the fact to the process or result of catching that ball.
While statisticians are right in identifying Tom’s experiences as nothing more than incidental events of what happened, this story can be categorically different from whether our universe’s characteristics are statistically significant or not. Two strings of letters can illustrate the difference. Imagine each sequence contains two million letters drawn from the English alphabet grouped into varying lengths.
The first example is filled with nonsensical character groupings. Although the probability of this particular arrangement for two million letters is vanishingly small, this improbability holds no statistical meaning. Any random string of two million characters would produce the same type of result.
To claim that this particular arrangement is significant would require starting with the result. That is, after encountering this arrangement someone then argues backwards for this arrangement to be statistically meaningful.
Now consider the second sequence filled with flawless fluent English communication. It too is just as improbable as the first one. Is the probability of this arrangement also statistically insignificant? No.
We accurately detect this is not a haphazard assemblage. Why? Because it conforms to a pre-existing standard, namely language. In this case, we start with language to evaluate whether probability suggests this particular letter arrangement could exist without authorship. Its existence without authorship is vanishingly small.
Similarly, whether the universe and the earth are rare is not based upon what happens to exist and any set of characteristics will do. Rather, a prior set of necessary conditions set on a razor’s edge are required for intelligent life.
Scharf admits, “if this is the one and only universe, with no universe before or after it, that raises the uncomfortable question of why it turned out this way: suitable for life”/1. Why is this question uncomfortable?
When open-mindedness drives our inquiry, then just as we conclude the second letter arrangement is significant, so too when our universe and earth correspond to a pre-existing set of narrowly defined requirements for intelligent life, this can not be dismissed outright as simply a posteriori reasoning.
1/ The Copernican Complex, pp. 31-32.