Lesson 4: The Origin of Knowledge 4.8 Where Scientists find Information What do scientists do as far as getting the "truth"? Of course, scientists are not so different from ordinary people: they don't know much about anything in great depth, except in their own specialty. But they do have a habit to trust their approved sources. Their highest category of believability, called "primary references", consists of refereed journals. These are journals where nothing is published that has not undergone rigorous review by experts (so-called "peer review"). Examples are the journals Science and Nature, as well as thousands of specialty journals, such as The Astrophysical Journal and The Journal for Geophysical Research. You will not, as a student without special background or special scientific ambitions, normally need to consult any such references. For broadening one's horizons, there are "secondary references", with articles that build on the primary literature. This is good stuff and includes books and magazine articles by reputable authors (those who have lots of refereed articles that stood the test of time). It may also include web sites by reputable organizations, especially those with the suffix ".edu" and ".gov" (because there are internal checks on publishing junk). Many science writers of books and magazine articles produce usable materials, especially if they took care to have their writings reviewed by experts. There are also at least one newspaper writer who qualifies as a source of reliable secondary material: John Noble Wilford of the N.Y. Times. We would like to think that our course also falls into this category, since we have a reasonable working knowledge of much of what we talk about here, or else have used reliable sources. Tertiary references (which build on secondary literature) are somewhat less trustworthy, of course, although things of interest may appear there, as well. In addition, there is much trash. This is mainly of interest in documenting the range of misconceptions that exist regarding any one topic of scientific interest. Good luck with separating the grain from the chaff. It is not easy.