– By Byron Jennings, Theorist and Project Coordinator
Sometime ago, one of my relatives told me that his son had shown evolution was not a fact. This set me to thinking furiously, as Hercule Poirot would say. No, not about the validity of evolution. I am not a biologist and besides evolution is one of the best-supported scientific models of all time, like classical mechanics in 1900. Ah, perhaps that is not the best example, but you know what I mean.
Rather, it set me to thinking furiously about how to explain what science is to the uninitiated. After hearing this statement, during my daily commute to and from work, I would think about what science is, how it works, and how to explain it to the general public. The result is given in my article in Physics in Canada and in this series of blogs. In the case of my relatives mentioned above, I suspect it would fall on deaf ears. After all, they listen to Fox News.
Evolution is not a fact. This statement strikes me as peculiar; like the statement: The number three is not green. Evolution is a model of how species arise. It makes about as much sense to ask if a scientific model (theory, law, paradigm) is a fact as it does to ask if a model boat is a fact. The question is poorly posed to the point of being meaningless. (There is no such thing as a stupid question but if there were that would be it.) But one hears such questions all the time: Is global warming a fact? Is it a fact the universe 13,4 billion years old? Is it a fact your mother wear army boots? (Well, maybe not the last.) It is also common for scientists to get that deer-in-the-headlights look when asked such questions. So what is going on?
The answer came to me in a lecture by Carl Weiman (physics Nobel Laureate and science educator). He pointed out that, in any field, the novice and expert view the field differently. Whether it is chess or biology, the novice tends to view the field as a catalogue of facts (an idea that goes back at least to Aristotle), and the important point is what are these facts. Hence the question: Is that a fact? i.e. Should it be in the catalogue? The expert on the other hand sees patterns, relationships and organization but has no catalogue of true statements. There is no need to remember individual pieces of information because they are inherent in the patterns and can be reconstructed from them. For the expert, it is the patterns and relationships that are important. In science, these patterns are called theories (although I prefer the term model). Thus, we have two incommensurate views (or paradigms) of knowledge: a catalogue of largely unrelated facts or a coherent framework (a model describing observations).
When the novice or layman asks if is it a fact, he wants to know if the statement is to be included in the catalogue. He knows nothing of theories as general organizing principles since they are not part of his understanding of science. As an example of this, see the Answer to the Complaint in the Kitzmiller v. Dover Area School District court case on the role of evolution in the classroom where it is stated: Defendants deny that the term theory, as used in science, has a distinct meaning and does not suggest uncertainty, doubt or speculation. The first response to this is: Can the defendants not read a dictionary? (Check the definition of theory in just about any dictionary). Are they actually that stupid? But that is not the problem: In their understanding of science, there is no place for general organizing principles.
Theirs is a Victorian (or Newtonian) view of science: Scientists, it seemed clear, began with careful observations, cautiously proceeded to a tentative hypothesis, progressed to more secure but still provisional theories, and only in the end achieved, after a long process of verification, the security of permanent laws. This view of science has been superseded, just as quantum mechanics superseded classical mechanics. Contemporary scientists, the experts in this case, have in their model of science no place for the catalogue of true statements or permanent laws. They have observations (whose interpretation is model dependent) and observationally constrained models, otherwise known as theories. Theories not in the sense of conjectures, but in the sense of general organizing principles: the special theory of relativity, quantum theory, or the theory of evolution. The scientist and the general public talk past each other using the same words, but meaning different things: Two cultures divided by a common language.
