"Bear in mind that the wonderful things you learn in your schools are the work of many generations, produced by enthusiastic effort and infinite labor in every country of the world. All this is put into your hands as your inheritance in order that you may receive it, honor it, add to it, and one day faithfully hand it to your children. Thus do we mortals achieve immortality in the permanent things which we create in common." - Albert Einstein

Tuesday, June 11, 2013

Scientific Theories Explain

After I finished college, I taught Chemistry to non science majors at the Ateneo. Unlike other lecturers, I did not choose to use a textbook specific for students that are not majoring in the sciences. Instead, I used the textbook that I had when I was taking first year Chemistry. I taught for two years and I did learn a lot about Chemistry during those couple of years. Teaching was quite different from just me sitting in one of the chairs inside the classroom as a student. I actually had to know the stuff that I was about to teach.

It is no wonder that some think that teaching is one of the effective ways to learn. Having the obligation to explain somehow forces a mind to understand. After all, one can not explain something one does not comprehend. In science, however, explanations are not really provided as options. A correct understanding of the nature of science leads us to a conclusion that a lot of people probably take for granted. In science, theories are the explanations.

Wikipedia provides the following definition of a scientific theory:

A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of knowledge that has been repeatedly confirmed through observation and experiment.

A theory is an explanation:

Above cartoon captured from http://web.missouri.edu/~hanuscind/8710/NSTA_Science101theorylaw.pdf
I copied the above cartoon from an article by William C. Robertson in the Science and Children journal of the National Science Teachers Association in the US. The article actually has a title that is in fact a misunderstanding of science so one should really read the entire article and not just the title, "Q: How does a scientific theory become a scientific law?" Obviously, an explanation of a law does not become a law, so the question indeed demonstrates a misunderstanding of what theories in science really are. Laws are basically summaries or collections of observations. These are descriptions of our world as we experience it. Robertson answers the question, How does a scientific theory become a scientific law?, with the following paragraph:
"... Theories generally provide mechanisms that explain the things we observe. There is a theory known as the kinetic theory of gases that provides a mechanism for understanding Boyle’s law. In the kinetic theory of gases, we make various assumptions about how the molecules in a gas act. In the most basic form, we assume that gas molecules run into one another without sticking and that they move about randomly. We assume that the molecules have an average kinetic energy based on the temperature. Those basicassumptions lead to Boyle’s law holding true. Because the kinetic theory of gases provides a mechanism rather than just a description of results, it qualifies as a theory. The kinetic theory of gases will never become a law, because that’s not what theories become. If a theory is any good, it explains a law. The kinetic theory of gases explains Boyle’s law, but the theory does not evolve into the law. The highest award for a theory is that it is a good theory, not that it becomes a law...."
One reason I learned a lot when I was first teaching Chemistry was that the explanation I had to give in class was in fact what Chemistry was all about. Theories are the explanations provided by scientists so that we could better understand the world we live in. Theories are the concepts, the substance of science. Teaching science means teaching its theories. The atomic theory of matter is how a chemist explains some of the things we observe like color, taste, odor, softness or hardness.

It is therefore baffling to hear someone say that when teaching science one must find different ways of explaining. Does that mean offering different theories? That, of course, is not possible. Only good theories should be taught although one can possibly present a bad theory to illustrate an example when a theory must be discarded. The theories are the explanations. So perhaps, it means to try and present the same explanation with different styles (like slowly and not too fast; or with slides not with chalk). Nonetheless, what is important here is to realize that since the main substance of science is its theories, and theories are the concepts, teaching science is indeed so much more than just teaching skills, it is teaching explanations.





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