In mid-Victorian times, Lord Kelvin peered down his nose at Charles Lyell’s estimation of sedimentation rate from the historic silting of the port of King’s Lynn, as a means to judge the vast time span represented by the stratigraphic column. His words were not kind; “…when you cannot measure [what you are speaking about], when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind”. Geologists cringed, particularly when Kelvin went on to reckon an age of 20 to 40 Ma for the Earth based on its cooling from a molten mass, using the physical laws of conduction and radiation. He was fundamentally wrong on most counts, partly because he knew nothing of radioactive heat generation nor convective heat transfer. Sadly his corpse could not be revived to eat his mean-spirited words. Nonetheless, the gibe of Earth scientists’ being “unscientific” has stuck. We rarely stick to the “scientific method”, reputedly stemming from the Elizabethan philosopher, Francis Bacon and his rationalization of the inductive method of reductionist experimentation. There are few universal “truths” in Earth history, and the interweaving of limitless processes with a vast spectrum of rates, scales and magnitudes renders reductionism absurd. Even more prone to reductio ad absurdem is the chemist Karl Popper’s supposedly logical insight that “proper” science rigorously subjects hypotheses to a “risky test”; an experiment that should yield evidence of refutation if the notion is unsound. Popper’s method of falsification consigns to the dustbin of research any hypothesis which fails the test, with the corollary that in is not “best practice” to seek confirmation for a hypothesis.
Carol Cleland of the University of Colorado (Cleland, c.e. 2001. Historical science, experimental science, and the scientific method. Geology, v. 29, p. 987-990) demolishes the “recipe-book” approach to science, which has laid a dead hand on not only the Earth sciences, from the standpoint of philosophy and reality. She starts from the position of Thomas Kuhn, by pointing out that, for Popper, the whole of Newtonian celestial mechanics should have bitten the dust when 19th century astronomers discovered that the orbit of Uranus deviated from Newtonian prediction. A sustained search for reasons why concluded that there must be gravitational forces from planets beyond Uranus, and sure enough astronomers discovered Neptune.
There is an air of bullying about the “scientific method”, which has warped investigations and dulled imagination and curiosity for centuries. It provides ammunition for those who carp and pontificate from the sidelines, and in many cases from positions of considerable power. Cleland does us all a service by discussing philosophical matters of science in the context of the realities that confront us all, in an accessible way. Her analogy is Holmesian detection (Sherlock was a deductionist, by the way, proceeding from the general to the particular), which discovers events and proceeds to trace their circumstances – the search, to my mind, for the artillery rather than a single “smoking gun” is far richer than the events themselves, because that deepens our sense of context for particular events, however dramatic they might seem to be.