what is the 'anthropic principle'?

The Creation Declares the Glory of God     God     

It Appears That This Universe Is Perfectly Tuned for Life on Earth!  

Life as we know it exists in a 'perfectly tuned' universe, and a 'perfectly tuned' earth.  Now, only one of two options can explain this business of our cosmos being 'perfectly tuned'.

 Matter came from nothing, and by chance slowly evolved into man
(Naturalism / Evolutionary Principles)

OR

The cosmos was created specifically for life - humans - to exist within it (Anthropic Principle.)

 
In other words, the Anthropic Principle states that it is logical to assume that if this earth was created for humans to live upon, then it would be suited for that purpose.  

Even the atheistic scientist Stephen Hawking acknowledges that the anthropic principle has merit and must be addressed:

“Why is the universe so close to the dividing line between collapsing again and expanding indefinitely?  In order to be as close as we are now, the rate of expansion early on had to be chosen fantastically accurately.  If the rate of expansion one second after the big bang had been less by one part on 10 to the 10th power, the universe would have collapsed after a few million years.  If it had been greater by one part in 10 to the 10th power, the universe would have been essentially empty after a few million years.  In neither case would it have lasted long enough for life to develop.  Thus one either has to appeal to the anthropic principle or find some physical explanation of why the universe is the way it is.”  

The Nature of Space and Time, Stephen Hawking and R. Penrose, pg 89-90

Just so we understand clearly how infinitesimal that the difference between the universe existing or not existing (at least in the mind of Hawking, an eminent cosmologist,) consider the number he quoted written in long-hand:

    1 / 100,000,000,000   -   One chance out of 100 BILLION that the universe COULD EVEN EXIST!

Clearly not good odds, yet this is just the beginning of the odds that the Naturalist and the Evolutionist must rely upon!  With these kind of odds, the Anthropic Principle, and the Creator behind it, does not appear to be improbable!

To add to these terrible odds, and to further the apparent design of the cosmos for the ability to sustain life, consider the following cosmological improbabilities (adapted from Reasons For Believing by Frank Harber):

The sun is 93 million miles away, and over 11,500 degrees Fahrenheit on its surface.  Its energy provides the heat which sustains life on earth.  It is in exactly the correct position for the proper temperature to sustain life on earth, because if the temperature on earth was 50 degrees more or less, life would cease to exist.

The earth rotates over 1,000 miles an hour.  If it were to slow down by just 100 miles an hour (one tenth,) life would be destroyed by excessive heat during the day, and excessive cold at night.  If the earth rotated faster, catastrophic winds would occur.

Consider the earth's crust.  If the earth were the size of an apple, the crust would be smaller than the apple's skin.  But if the earth's crust were only 10 feet thicker than it is, the additional matter would oxidize all available oxygen from the air, making life impossible.

 These are just a few of the dozens of items that are necessary for life as we know it to exist on the earth.  This list grows longer with every year of research.  In 1966 there were thought to be eight different life sustaining requirements.  That list has grown to over forty now.  A fascinating analysis of these requirements is found in  Dr. Hugh Ross’s The Creator and the Cosmos.

Arguments against the Anthropic Principle:

Objections to the Anthropic Principle can be summarized into three responses:

1) We would not be here to observe the universe unless the extremely unlikely did take place.

Essentially, this argument says "it's all a coincidence.  Because in fact we are here, that proves that the improbable did happen."  This is an appeal to infinite chances, which is an absurd notion.  Infinity is a meta-physical notion, not observed anywhere in nature.  William Lane Craig has created an analogy that describes the issue well.  Suppose a prisoner was to be executed by a firing squad consisting of 100 sharpshooters at 10 paces.  If the prisoner survives the firing squad, he would certainly be surprised.  He could safely assume that  there was intent behind his survival, since the odds of all 100 sharpshooters missing are absurd.  Hence, when we consider the odds of our cosmos sustaining our life, we can safely assume intent behind our existence.   

 2) The design of the universe is mere anthropomorphism (human arrogance in interpretation)

 Joseph Silk likens his argument to a flea, considering that a dog has been designed solely for his existence.  This argument has several major flaws.  While the flea is a little self centered in his conclusion, there is still no reason to not consider a purpose for the dog.  In addition, the flea, while perhaps preferring to live on the dog, has many options that would maintain his existence, including cats, rats, etc.  There is absolutely no possibility of another design even conceived that could sustain life as we know it. 

       
3) Design arguments are outside the realm of science, and must be ignored

 But science is rarely religiously neutral.  When it comes to cause, two possibilities exist:  Natural and Supernatural.  To dogmatically assert that supernatural answers can never be considered is equivalent to demanding that all people adhere to one religion, namely atheistic materialism. 

 
In summary, the Anthropic Principle is a valid argument, lending us further to consider a Creator for the Creation.