The Galileo/Copernican and the Ptolemaic views of the solar system lay in dispute for the 150 years between Galileo and Newton (specifically between the dates of the publication of Copernicus De Revolutionibus and Newton’s Principia). In the period of time between these events, with the possible admission of Kepler’s third law) there were no facts to distinguish these theories. In fact, glancing far to the future, the negative results of the Michelson-Morley experiment demonstrating that the Earth was at rest would have been a point to the Ptolemaic not Copernican view. The scientific (heuristic) passions of the proponents of the Copernican view is what drove the outlook of astronomers to the point where at the publishing of the Principia the Copernican viewpoint was dominant. Attached to the prologue of Galileo’s thesis was a forward by Osiander expressing the point that this view was not necessarily “true” but instead was a “fruitful” way of approaching astronomy. This is a red herring. Ptolemaic astronomy was a fruitful source of inquiry for thousands of years. Astrology has been fruitful employment for 2500 years, Marixism was (and remains alas)
a fruitful mechanism for obtaining political power. Fruitful by itself is not sufficient. Theories are fruitful in that they are believed to be fruitful mechanisms for getting to the truth of reality.
In 1914 TW Richards was awarded the Nobel prize for an extremely accurate measurement of atomic weights. Fifteen years this result was completely scorned as useless, for as that measurement made no allowance for isotopic ratios those painstaking measurements were rendered useless. This was a measurement, of high accuracy, of a value that was discovered to have no correspondence to any features of nature. Accuracy qua accuracy is of no value. One misconception about science is that it is experiment that drives progress. Yet it is theory that is required before experiments to provide the basis for how experimental data is interpreted and in fact for what experimental data is deemed to have any value at all.
New visions and insights drive theoretical breakthroughs. Yet the history of science is littered with far more failures than success. This is not limited to “lesser scientists”. Einstein’s vision following Mach imagined Relativity and against Mach solved Brownian motion. Yet Einstein same said vision rejected quantum randomness. Major theoretical breakthroughs in science require a major reworking of our view of nature, a replacing of an older view with a newer one. Proponents of the new, driven by their heuristic passionate belief in the correctness of their vision, must pursuade on the basis of future intimations of fruitfulness in the search for truth of their vision. In doing so, they also must invalidate the older vision. This process of invalidation is often rancorous and ugly. This “feature” is common and perhaps not easily escapable.
This then suggests some striking things about the scientific process. Theory preceded and both validates and interprets experiment. Major theoretical breakthroughs require persuasion. The passion of scientific discovery must be transformed and moved to the passion of persuasion that the new vision of the truth has intimations that it might be fruitful for further deepening of our understanding of nature. Yet a problem remains. Is there anything left? What differentiates the project of chasing the structure of matter at CERN and Fermilab from astrology? Why was it right for the Copernican view to supplant the Ptolmaic in the period between Copernicus and Galileo and before Newton? There are good answers to these questions but that will have to wait until a later essay.
The first parts of this essay draw heavily on Michael Polanyi’s Personal Knowledge which is an epistemological inquiry looking toward a “post-critical reality” epistemic framework. It might also be noted, this book predated Thomas Kuhn’s The Structure of Scientific Revolutions. Critical reality is the idea that our physical theories accurately represent reality. This is in contrast to the Positivist (which is not as far as I can tell the same as Logical Positivism). This view espoused for example by Stephen Hawking suggests that the question of whether the underlying matches the theory is irrelevant and that physics (or theory in general) merely is a mechanism for predicting experimental results.