CPT Q. 035: How does the usual need for ‘auxiliary hypotheses’ impact your own modeling endeavors?

Q. 35. How does the usual need for ‘auxiliary hypotheses’ impact your own modeling endeavors?

Fuller question: In their paper: “Verification, Validation, and Confirmation of Numerical Models in the Earth Sciences,”¹ Oreskes et al. present a succinct summary of what is faced in any model-building exercise:

“The additional assumptions, inferences, and input parameters required to make a model work are known as ‘auxiliary hypotheses’. The problem of deductive verification is that if the verification fails, there is often no simple way to know whether the principal hypothesis or some auxiliary hypothesis is at fault. If we compare a result predicted by a model with observational data and the comparison is unfavorable, then we know that something is wrong, and we may or may not be able to determine what it is. Typically, we continue to work on the model until we achieve a fit. But if a match between the model result and observational data is obtained, then we have, ironically, a worse dilemma. More than one model construction can produce the same output. This situation is referred to by scientists as nonuniqueness and by philosophers as underdetermination.”

In light of Oreskes et al., how do you view your own modeling work?

Response: I see the quest to understand just what took place during the Flood as similar to that of putting together a complicated puzzle. There are literally tens of thousands of professional peer-reviewed papers on various aspects of geology, geophysics, geochemistry, and many other aspects of earth science. These today provide a wealth of observational data plus a wide spectrum of interpretive schemes, which in many cases conflict with one another, attempting to fit these data together into a coherent and consistent framework. As Christian believers we have additional extremely important data in the form of eyewitness accounts of certain key aspects of the earth’s past.

One of the biggest challenges in the quest to understand the Flood for a believer is that of not getting utterly overwhelmed by the sheer magnitude of the available observations, observations which presumably need to be accounted for, at least at some level, in any serious attempt to understand and describe the Flood. For many, I’m sure it seems that there are so many trees that determining the scope and larger character of the forest is nigh to impossible.

Given this state of affairs, to me the primary issue is not really model building or model validation. To me the primary task is much more basic. It requires sorting through the vast number of observations, many involving highly complex phenomena and processes, to identify the mere handful that are most significant and strategic in assembling the big picture. Some of these critical observations might well include, for example, the large-scale topographic features of the earth such as the continents and ocean basins, the major continental mountain belts, and the mid-ocean ridge system. A next plausible step would be to identify candidate hypotheses or conceptual frameworks that offer a reasonable likelihood for successfully integrating these most significant pieces of the puzzle. To me it is not until this stage that it makes any sense at all to begin applying some of the standard modeling tools available for the purpose of perhaps fitting together a few more of the major pieces of the puzzle.

In an extremely brief way that is how I would characterize my efforts over the years to try to begin to understand what took place during the Flood, that is, mainly of trying to identify the most strategic issues and from these to seek to fit some of the most important pieces of the puzzle into place.