What makes any investigative field a scientific discipline? This article argues that disciplines are ever-changing frameworks within which scientific activity is organised. Moreover, disciplinarity is not a yes or no proposition: scientific activities may achieve degrees of identity development. Degree of consensus is the key, and consensus on many questions (conceptual, methodological, institutional, and social) varies among sciences. Lastly, disciplinary development is non-teleological. Disciplines pass through no regular stages on their way from immature to mature status, designations articulated within the (...) rhetoric of discipline formation. Scientists assemble disciplines using many elements: phenomena, methods, instruments, theories, analytical techniques, and institutional tools such as journals, government bureaus, and university positions. Scientists created geophysics during the nineteenth and twentieth centuries through such a combination. Whether geophysics became a discipline depends on how discipline is defined. (shrink)

The usual problems of measurement and its meaning are complicated and magnified when the object of study is in principle and in fact inaccessible. When a phenomenon occurs in a place where our instruments cannot reach, what can the relation between the instrument, its reading, and the phenomenon be? This essay asks how researchers have addressed questions about inaccessible processes of Earth's magnetic field on the surface, at the edge of space and under its surface. This case takes us beyond (...) simple contrasts of inductive and deductive methods, or field sciences versus basic sciences, to a messier, more nuanced view of inherently complex sciences. The article focuses on investigations of Earth's magnetism and electricity, but its perspectives are applicable to many areas of recent science. (shrink)

This book joins a small number of efforts in the last decade to present the complex scientific issues of geomagnetism to a broader, semi-technical audience. The author approaches this goal more closely than most scientists and science writers. He specifically eschews mathematical equations knowing that even one equation leads some readers to give up trying. He offers instead a mix of description and story-telling, the former directed at phenomena and procedures, the latter drawn mostly from personal experience.As Merrill notes, his (...) wife insisted that he “explain the material in a way she could understand it” (vii). A virtue of this is an enforced candor often obscured by mathematics, even in semi-popular accounts. This is most clear in addressing fundamental questions, such as when he asks what produces the magnetic field of magnets. In a paragraph that begins with a simple bar magnet, the author successively halves the magnet until he has only an electron remaining. This he calls a po. (shrink)