Science as fact

Justin Harris at Sophorist.com posts on teaching macroevolution as fact. (He concedes that we can breed dogs, hence "macro".) His objection is that it is taught as fact and that no competing theories are advanced. I shall reply.

All science is taught as fact and no science is ever taught as theory, or definitional, or open to more sophisticated analysis. The history of science is presented as the clear and unambiguous advance of knowledge against superstition. Just this past Friday I overheard students wonder how the planets got their names. I began explaining and we moved along to the days of the weeks when a student asked about Sunday, since the Sun is not a planet. Oh, but planet just means wonderer, I explained and the ancients numbered it as one of the things that moved across the sky. Another student firmly asserted that the Sun did not move, they had learned it in school. Aside from the movement of the Milky Way from galactic central point, the rotation of the outer spiral arm of the Milky Way and hence the solar system around the center of the galaxy, and the very curious notion that such an object as the sun is fixed in place and is not pulled upon by other heavy objects, I asked the student if he could prove that it was the sun that moved and not the earth. This is a question of relativistic motion. Apparently, the teacher who had passed on this bit of cosmology has closed the door on Einstein. As a result, whoever attempts such a task must unteach some old ideas and replace them with better ideas. And this all relates to the movement or presumed stability of the sun. Imagine more complex ideas, like the evolution of species.

Science is all theoretical (in the common English usage) because it is tentative. If students were to ever come away from science with the kind of knowledge included in these course materials, this would not be an issue. Students would understand that some of what they understand to be the nature of things will be revised. My own grandmother was once taught that the atom could not be split. That has since been rejected in favor of an explanation that includes fission.

This is a particular irritation to those of us who are historically minded and see the advance of thought as including errors as well as improvements. Science texts in the public schools which pretend to an advance of inherently obvious knowledge create a false authority for science, one that science does not claim for itself (though some practitioners will).

finally that leads us to alternate theories. Well, in science class, these alternate theories should conform to the same rules as all the other science material ought to in terms of its emperical validity, framwork in a testable hypothesis, and so on. There are a good number of subjects in which science can say very little, although scientists can speculate just like anyone else on the street. Michael Crichton has useful things to say on this subject in two of the speeches up on his official website. Speech 3 and 4 adress the questions of speculation and political advocacy in science. Crichton likes neither.

Since I have followed human evolution, quite a bit has changed. The science of human evolution is quite young and just looking over the conventional wisdom of the past 30 years one can be surprised at just how much has changed. After all science is tenative. Sometimes, the whole framework is overthrown (the famed paradigm shift of Khun's scientific revolutions). This has certainly happened in politics during my adult awareness, as the Cold War ended, but it has not happened in the areas of science I pay most attention too. I hear stirrings on the nature of time, but I don't follow it to closely. In any event I am happy to witness a new understanding overthrow the old one in the question "where did we come from," but any explanation needs to deal seriously with the observable phenomena, like the fossile record and radiological dating. Any explanation needs to avoid untestable hypotheses, speculation, and conjecture. When students ask questions that cannot be answered scientifically in a science class, teachers should begin by explaining what science can and cannot answer. Its handy to have scientific annecdotes on hand to illustrate this point. Then one might venture into speculation (students may insist) with an obviously open mind, since one is speculating, and conclude with a solid barrier between speculation and the scientific method.

Say a student asks about extra-terrestrial life. One could immediatly reply that there is no verifiable evidence of any despite fourty to fifty years of search. Remind the class that negative evidence is not proof. If they want more, discuss the issues, express multiple points of view from a variety of sources, and conclude nothing except that we do not know much more than we did before Sputnik (or Columbus for that matter) and remind the class that work in this area is speculative. Point to empirical evidence of your next topic and move on.