Scientific dogma—a personal experience

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Abstract

“I am skeptical of the principle of objectivity, which, in my view, is often simply the current popular viewpoint in disguise” (D. Reanney, After Death, Morrow, New York, 1991).

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The Collins English Dictionary defines the word dogma, in part, in the following manner “a belief, principle or doctrine” and the adjective dogmatic as “forcibly assertive as if authoritative and unchallengeable”. History is replete with numerous examples in connection with all aspects of human endeavour, notably in religion, but also in the arts and sciences. In fine art, one can only imagine the frustration experienced by the early Impressionists in facing the strictures imposed by the Salon during exhibitions. Medicine gives us the classic example of the causes and treatment of scurvy. Sailors in the British Navy suffered greatly from this affliction with the accepted remedy proving to be useless. The real tragedy is that several individuals, including the legendary Captain Cook, had noted that consumption of fruits such as lemons ameliorated the problem, and duly recorded their observations (hence the eventual description of British people as “limeys”). However, the Admiralty at that time would have none of this and persisted for many years in propagating the accepted dogma.

In the present Editorial I would like to share with our readers a personal scientific example. This story begins with the brilliant research of Pierre and Marie Curie in the 1890s leading to the discovery of the phenomenon of piezoelectricity. Many years later Sauerbrey¹ gave us a model for the behaviour of acoustic wave sensors that has now evolved into what has become widely known as the “quartz crystal microbalance” (QCM). In essence this model involves an extension of acoustic wavelength when material is added to the surface of a piezoelectrically oscillating device in the gas phase. Sauerbrey pointed out that for a very thin film and with the assumption that the added substance has identical properties to quartz, the device is responsive to mass, hence the “balance” notion. A simple, widely quoted theoretical equation relating frequency changes to added material was developed in connection with the model. The problem begins with attempts to transfer this idea to the deposition of films of “plastic substances” such as polymers and proteins etc when the device is operating in fluids. In this case, unlike the situation for the gas phase, acoustic energy is propagated into the fluid through the solid–liquid interface. It turns out that the nature of this transmittal of energy is exquisitely sensitive to the conditions at the interface rendering the liquid-phase acoustic wave device a particularly useful tool for the study of interfacial phenomena.² Despite increasing evidence that charge, coupling effects and free energy etc really govern the behaviour these devices in liquid the dogma persists that the structure is a “microbalance”. A rather good example among many was a recent article I reviewed where the authors assigned an upward shift in frequency in liquid to an organic ligand stripping ten layers of gold off the sensor electrode. In order to explain a subsequent reversal in frequency back to the original level the authors then proposed a re-deposition of the gold complex!! Despite my review, the Editor chose to go along with the “balance” dogma even in the face of the suggested preposterous chemistry.

In terms of applications, the mass concept is often invoked to ill-advised levels in electrochemistry where the QCM has become an accepted tool. In this field we often see Sauerbrey computations to the last molecule in terms of electrode reactions and the like. The problem emanating from this dogma is not so much that the mass model is invalid, but that the tremendous sensitivity of the technique to interfacial physical chemistry remains under-explored. At stake, as just one example, is the detection of the tertiary structure of biological macromolecules when they are attached to the surface of a substrate that is immersed in a fluid. This has been an intractable problem for years in the area of biophysics. Another would be the possibility to examine the important physics of interfacial hydrodynamics.

The origins of dogma have attracted sociologists, philosophers and many other groups for a long time. So what is responsible for the dogma outlined above. Resistance to change surely plays a major role but more insidiously in the acoustic wave example, vested interest raises its head. Large numbers of papers have been based on the measurement of mass by the acoustic wave sensor and a number of instrument Companies have proven adept at satisfying this “market”. Clearly, individuals are notoriously reluctant to “stick their head above the parapet” despite the burgeoning evidence that is contrary to the existing thesis. A further element is that a simple notion and equation is easy to understand. The complexity of all that is entailed in the interaction of high frequency waves with the interfacial chemistry of the solid–liquid interface is much harder to grasp, let alone use in applications.

An intriguing ancillary issue to scientific dogma is the strongly connected role of the peer review system and Editorial practises of major vehicles for the publication of scientific research. We pretty well all accept that rigorous “justification” of arguments generated from chemical and other data is the order of day. I would argue for more flexibility and a greater sense of recognition from peers when considering the results of difficult and groundbreaking work. In this respect, I am reminded that Lord Rayleigh³ commented that the Joule–Thompson effect was predicted years before the seminal work appeared, but the truly original paper by Waterston was rejected. The same fate awaited an important paper, eventually published by Michael Smith on site-directed mutagenesis and we all know where this work ended.⁴ It is entirely possible that a prevailing level of dogma was involved in these decisions.

Michael Thompson

Scientific Editor, i-section

References

1. G. Sauerbrey, Z. Phys., 1959, 155, 206.
2. J. S. Ellis and M. Thompson, Chem. Commun., 2004, 1310.
3. Scientific Papers of Lord Rayleigh, Dover, NY, 1964, vol. III, p. 558.
4. During the presentation by Michael Smith to The John C. Polanyi Nobel Laureates, Lectures, November 3, 4 1994, Toronto, Ontario. Also, see Science and Society, ed. M. Moscovits, Anansi, Concord, Ontario, 1995, p. 69.

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