How Galileo Helped My Testimony

By Jason Rose


In the sciences, a model is an idealized description of the real phenomena we observe in the world. We construct models (physical models, diagrams, mathematical equations, etc.) for many reasons. Our motivation might be to use our model to predict outcomes or to use the knowledge provided by our model to control the outcome of a complicated system. Sometimes we construct a model to see if the logical consequences of our model will agree with what we observe, thus validating that the rules and relationships we’ve proposed in our model have meaning in the real world.


Constructing an idealized model and using it to predict, control, and understand what will happen in reality is useful in all aspects of learning, both temporal and spiritual. As we learn principles of the gospel through the scriptures, through teachers and leaders, and through our own experiences and personal revelations, we construct our own internal model of how the world works and what the important underlying principles are.


As we gather more data through study and experience, we may find the need to refine our internal model. Sometimes we find evidence that our model has serious flaws. In Faith is Not Blind, Elder and Sister Hafen describe three ways we might react when confronted with flaws in our model. We might deny the evidence and stick to the old model, we might despair of creating models at all, or we can work to create a new model that incorporates the new information as well as all of the things that the current model could do. Examples of these three reactions (denial, despair/resignation, and constructive improvement) have occurred throughout the history of science.


A good example of these reactions is the shift from a geocentric view of the universe to a heliocentric view. At the time of Galileo (1564-1642), the accepted model was that the earth was the center of the universe with the sun and the planets moving around it. In this view, the sun would circle around the earth, but, in order to match the available data, the planets would have to execute complicated orbits that sometimes made them appear to reverse direction. This view had already been incorporated into people’s religious views, and they could cite scriptures such as Psalm 93:1 “…the world also is stablished, that it cannot be moved” to prove their point. Proponents of heliocentrism saw that the descriptions of the planets’ orbits would be much simpler in a model where the sun was at the center instead of the earth. Galileo, after hearing about telescopes, made his own telescope and undertook a careful study of the night sky with it. The things he observed, such as moons circling Jupiter and Venus demonstrating all four phases just like the moon, indicated that the simpler Heliocentric view was probably correct and Galileo publicly advocated for the motion of the planets around the sun. How would you react to this type of paradigm shift? Would you deny the evidence? If so, you would join the company of those who accused Galileo of heresy. His accusers forced him to recant his beliefs and to live under house arrest for the remainder of his life. Would you have despaired of finding any resolution? Many today talk about a conflict between science and religion that they often treat as unresolvable. Others found ways to incorporate Galileo’s observations into their internal model of the world. Heliocentrism has been further refined. The sun is the center of our solar system, but it is not stationary, and it is not the center of the universe.


It may be tempting to portray Galileo’s story in simplistic terms: science good/religion bad. The full story is more nuanced. There were also scientific arguments against heliocentrism; for example, if the earth moved, why didn’t the constellations appear to change shape as our perspective changed in moving from one side of the sun to the other? It turns out that they do, but the stars are so far away that the changes are so tiny as to have been impossible to measure in Galileo’s day. 


Probably the most important thing to learn from Galileo is that models have limitations. When we discover these limitations (i.e. when we find a gap between reality and our model’s predictions), this doesn’t signal intellectual or spiritual defeat, but an opportunity to take our understanding to a deeper level.


It is also important to realize that when an old model is replaced with a new one, the old model is not completely discarded. Even the geocentric model still has value; the moon and other man-made satellites do orbit the earth and when we need to understand the relationship between the earth and the moon, we can get fairly accurate results by assuming that the moon is moving around a stationary earth (even though, in reality, the earth and moon revolve around their center of mass which is, in turn, revolving around its center of mass with the sun).


A good example of how one model can succeed another without making it completely obsolete is relativity. At the beginning of the 20th century, it was known that light could behave like a wave. Waves in the ocean propagate by raising and lowering water and sound waves propagate by increasing and decreasing pressure in air. It was, therefore, logical to assume that light propagated in some (hard-to-detect) medium. This hypothesized medium was called “luminiferous ether” and science set out to discover it. If the earth was moving through the ether, then light should travel faster in directions that went with the ether and slower in directions that were against the ether. But no such difference in the speed of light could be detected. This seeming paradox, that light has the same speed in all directions, lead to Einstein’s theory of special relativity and its eventual refinement, general relativity. Relativity meant that when objects moved at speeds nearing the speed of light, their masses increased, thus altering the laws of physics a bit. But when objects moved at everyday speeds, the rules of relativity reduced to the usual laws of Newtonian physics that had already been used successfully for over two hundred years. Thus the new model, relativistic physics, didn’t make the old model, Newtonian physics, obsolete. Instead, the new model extended the old model to be applicable in more situations. The old model became a special case of the new.


Scientific modeling teaches us that when we discover gaps between what our idealization of the world predicts and what we observe, it is not something to cause us to deny or despair, but instead it is an invitation to deepen our understanding and construct new models that more accurately describe what we observe. Principles that we have already proven are not likely to be discarded, but rather subsumed into a larger theory with wider application to our lives. Brigham Young said, “Our religion is simply the truth” and it “embraces all truth that is revealed and that is unrevealed, whether religious, political, scientific, or philosophical.”  When we encounter gaps between the ideal and reality, we don’t need to fear, but instead we can press forward to deepen our understanding and knowledge of the truth.