The Three Sides of Spectroscopic Investigation

The rather peculiar title of this editorial attempts to provide a framework that I have found convenient for considering scientific developments. The first part of the concept involves the classical view of scientific inquiry, that theory guides application. That is, a theoretical framework is developed from which applications spring. Put more colloquially by the baseball catcher Yogi Berra, “If you don’t know where you are going, you’re apt to end up somewhere else”. Abundant examples of this approach can be found. For example, nearly 40 years elapsed between the first description of mass spectrometric principles and their initial application to chemical characterization. Similarly, NMR and Mössbauer spectroscopy were described theoretically long before their application. In the area of physics, the principles of laser operation were established long before a workable system was designed; the use of lasers in chemistry took even more time. This classical view of scientific inquiry can be represented as:

Excellent examples of how analytical spectrochemistry has benefited from fundamental findings in atomic physics were provided by the Dutch physicist C.Th.J. Alkemade, then at the University of Utrecht. He stated the philosophy clearly: “Analytical systems can be improved more straightforwardly and more universally if one first understands the basic mechanisms involved and has knowledge of the relevant physical parameters and constants.”

The converse side of scientific inquiry is that applications drive theory. In many situations, a sufficiently important application requires that the pertinent theory be developed so an applied problem can be better solved. An appropriate example lies in the field of atomic spectroscopy, which stems largely from the original work of R.W. Bunsen. Long before the Bohr model of the atom was formulated, Bunsen and his colleague Kirchhoff showed that a chemical flame and spectroscope could be used for the determination of alkali metals. This general approach can be embodied as:

The processes involved in these two “reactions” are mutually supportive and essential for scientific progress. No matter whether an investigation begins with an important application or a new theory, the opposite partner will benefit. For example, in NMR spectrometry, theoretical developments led and workable instrumentation followed. But when it became evident that NMR could solve important problems in chemistry, medicine, and other fields, the theory was refined further, to encompass the use of multiple pulse sequences, relaxation times, and other parameters to elicit additional information. In turn, those multidimensional parameters enabled even more complex problems to be tackled, and so on. 

In both cases, whether theory guides applications or applications drive theory, the NMR example suggests that instrumentation provides a catalyst; it serves as an enabler for theory to solve important problems or for problems to be investigated more fully and lead to improved theories. Instrumentation therefore serves as the third “side” of spectroscopic inquiry. The theory of multi-pulse sequences in NMR was of little use until it could be embodied in scientific instrumentation. Similarly, applications of NMR instruments to real problems suggested the importance of other parameters to characterize. Thus:

It is critical that this symbiosis not be overlooked by spectroscopists, other scientists, scientific journals, and especially funding agencies. It is worrisome that such a strong emphasis seems to exist right now in the funding of focused applications of existing theory or instrumentation. Funding mainly application-oriented research and neglecting either instrumentation development or fundamental underpinnings limits future gains needlessly. Instead, it seems prudent to dedicate an ongoing effort to both theoretical work and instrumentation development, even when the immediate application of a new instrument or theory isn’t immediately evident. Witness, for example, the development of scanning tunneling microscopy or, as mentioned above, NMR.

Hopefully, the foregoing comments provide convincing evidence that there are not two but really three areas of scientific inquiry: theory, application, and instrumentation. Each is capable of existing and being important on its own, but all benefit from symbiosis. The transfer of information between theory and applications will be driven not only by instrumentation but also by individuals who seek to recognize the importance of instrument and method development and who attempt to understand the fundamentals of instrumentation and the measurement process in greater detail. I am certain you will find that the articles in this issue of The Spectrocopist provide good examples of this symbiosis at work.

Gary M. Hieftje

Guest Editor

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