observing the unobservable without visualization

Bohr’s atomic model was developed in 1913, and was a natural progression from his contemporary Rutherford’s model of the atom as an entity with a dense nucleus and electrons in orbit around it. Importantly, Bohr’s model accounted for the discrete spectral lines found in hydrogen whereas Rutherford’s model could not. Bohr postulated that an atom consists of orbiting electrons which can instantaneously “jump” to different quantized, discrete energy levels. Rutherford held that these quantum electron jumps were too difficult to visualize. This begs the question: are scientific theories required to be visualizable? While a theory that uses only entities and behaviors that are visualizable makes it more easily communicable, it does not need to be a strict requirement because scientific theories that are not visualizable can still provide powerful predictions and explain underlying causal structures, which I hold to be inherently valuable in themselves.

The trouble with defining a scientific theory has to do with the fact that these theories must be both scientific and useful. However, these terms are not black and white, and can sometimes conflict or overlap with one another. I take scientific to generally mean something derived from applications of the scientific method — by most definitions, the scientific method requires the following three steps: abduction (the process by which scientists create a hypothesis that is the best explanation of phenomena), deduction (inferring what should be the case if the hypotheses are the case), and induction (testing the hypothesis). I take useful here to mean pragmatically useful; a theory that can be applied to inform predictions or explain phenomena which can then be used to undertake more scientific inquiry. It does not make much sense for a theory to be labeled scientific, however, if it is not also useful. Because Bohr developed his theory through applications of the scientific method, I hold that the concern here has to do with its usefulness. That is, in order to determine whether a scientific theory must necessarily be visualizable, we must ask whether the usefulness of a theory is inextricably tied to its visualizability.

If we can show that a theory that was not visualizable at the time of its conception was later found to be useful, we have shown that visualizability is not a necessary condition for usefulness. Bohr’s atomic model was useful according to my definition: it accurately predicted spectral lines in hydrogen, it directly led to explanations of electron behavior such as Bohr’s quantization rule, and laid the foundation for other scientists to explore frameworks of quantum theory such as matrix mechanics and led to such discoveries as Heisenberg’s uncertainty principle. Bohr’s atomic model, though not visualizable, played a part in developing an entirely new direction of physics and directly led to new scientific discoveries and thus can be said to be useful.

Further, it is not useful to immediately dismiss a scientific theory simply because it is hard to visualize right now — we may be able to visualize it in the future through better technology, for example. The theory might also be difficult to depict under the current scientific paradigm, but this lack of visualizability might also provide a reason to break out of the paradigm in the form of a Kuhnian anomaly and subsequent paradigm shift. These anomalies are extremely useful because they incite revolutions and new schools of thought which may be able to better explain phenomena in the future. If we dismiss a theory simply because we cannot visualize it, we lose the potential for a paradigm shift.

A potential cause for concern might be the counterargument that unvisualizable scientific theories are simply not pragmatic because of a difficulty to communicate them. While this incommunicability is a valid concern, and theories that are more able to be explained to laypeople or those unfamiliar with a specific field will likely hold more explanatory power, the theory will still be useful for the most part. That is, scientists in the field will still be able to use the theory, and have the potential to create more widely understandable explanations from the groundwork that the initial theory has laid.