An essay donated by Dave Wilson
The improbability of the Universe as it now exists
One of the arguments for the existence of God is the extreme improbability of a universe and a world such as ours evolving from the structureless and fiercely expanding blob that existed immediately after the Big Bang. Surely the complexity and degree of organization of living beings is improbable to the point of being inconceivable without the existence of some organizing, purposeful Being or Force to impose this order. In proposing to use this argument, however, one must take care to use the theory of probability correctly.
Regarding the extreme improbability of the universe evolving along the particular path it has taken since the Big Bang, it is easy to make a serious error in the use of the theory of probability. Let me illustrate with a very, very much simpler example of this error. Say that we have a fly free in a room at point A at time zero, and at a time 30 minutes later the fly is at point B. AT TIME 0, you would calculate (correctly) the probability of the fly being exactly at point B 30 minutes later as being very, VERY small. However, AT TIME 30 MIN, the probability of the fly being at point B is equal to 1—dead certainty. However, one does not say that the fact that the fly is now at point B is a miracle and attach a great deal of philosophical significance to this. In fact; the probabilities at time 0 of the fly being at point C, point D, etc. at time 30 min, are all extremely small, although it is certain that the fly will be at some point in the room.
One can make a similar argument about the path that our galaxy has taken to coalesce after the Big Bang and then to evolve and eventually develop at least one planet on which sentient life has developed. If we start only a billion years or so ago on this planet (stromatolites and bacteria?), a prediction that evolution would eventually produce wombats, snow leopards, screech owls, and man would be associated with an extremely small likelihood of occurring. On the other hand, a prediction that any other detailed path would be followed out of the virtually infinite number of possibilities would also have an extremely small probability of occurring. So the probability argument for the existence of an ontological force (a.k.a. God) runs into difficulty.
On the other hand, sorting out the details of how the universe (or at least that part of it which we can study) has evolved, and which particular one of the huge number of possible paths that could have been expected back “at the beginning” was in fact followed, is certainly a most challenging and fascinating business. So is the task of using science to try to predict at least some of the more important properties of the path the universe, our world, my country, my city, etc., will take in the years to come.
Originally posted: 2013-JUL-19
Latest update: 2013-JUL-19
Author: Dave Wilson