The prefix “pseudo” is derived from a Greek word meaning “false.” Pseudoscience refers to theories, assumptions, and methods that are mistakenly thought to be scientific. Obviously the distinction between science and pseudoscience is not clear-cut. Pseudoscience overlaps with scientific “misconceptions” - beliefs that are held by students and the general public that differ from scientific fact. Both of these concepts are subtle ones, since all scientific theories can be regarded as tentative to some degree.

At the 1996 IAU conference on astronomy education in London, UK, Neil Comins classified astronomical misconceptions into about 20 types, and he has described these in detail in his book Heavenly Errors (Columbia University Press, 2001). Some misconceptions are cognitive in nature; they are dealt with in our Part II. Others are products of religious belief or superstition (often transmitted through the “authority” of family or friends), or popular culture, or errors or excesses of the media. In relation to astronomy, notable pseudosciences include astrology, space aliens, and creationism; the works of Velikovsky also fall under the pseudoscience rubric. The majority of students will be affected in some way by these beliefs.

How to deal with them? The theory of constructivism is one of the most influential sciencelearning theories in schools today. It states that, by reflecting on their own knowledge and experiences, students build their own new knowledge about the universe around them. Teachers must therefore be aware of students' pseudoscientific beliefs, as well as their other misconceptions, if they are to correct them through their teaching. Many of them are deeply rooted. They cannot easily be changed by lectures and textbooks. They must be confronted through minds-on teaching.