Like Beauty in Sport, Beauty in Science also proves easier to define and understand than Beauty in Art, particularly with an example of the contrast between an “ugly” theory and a “beautiful” theory. Towards this end, consider the historical attempt to understand the motion of the planets in the nighttime sky. For centuries, the dominant theory in the West was that all the planets orbited around the Earth in concentric circles. A elegant idea in conception, it turned into a very ugly theory when put into practice, for the simple reason that it did not match well with the observed data. When actual observations of the night sky were compared with the geocentric model, it seemed as though sometimes the planets were reversing direction and moving backwards, speeding up and slowing down, or simply not appearing where they were supposed to. So in order to keep the theory alive, the idea of “epicycles” was invented, smaller circular paths that interacted with the larger orbits and caused all the observed eccentricities.
What made this an ugly theory was partly that it was hugely complex, hard to understand, and frequently inaccurate, and partly that it was filled to the brim with what is often called “fudge factor,” numbers and calculations added for the specific purpose of getting the data to come out right, but without any larger justification or explanation. In the case of the geocentric theory, there was no explanation for the epicycles, or how big they were, or how many of them there might be. They were added solely to make the larger theory less flagrantly wrong all the time.
In contrast, the eventual heliocentric theory of the solar system was a very beautiful theory. It is simple, and easy to understand. It can be explaned in a single sentence, which even most non-scientists can understand: “All planets move around the sun (in orbits that are shaped like ellipses with the sun at one focal point).” It matches all the observed data with a high degree of accuracy, and without any need for “fudge factors.” In addition, it makes clear previously unsuspected new insights. For instance, the variability in the speed of the planets is completely predictable from the observation that a line between the sun and any given planet will trace out an equal area in an equal amount of time for any portion of its orbit, a result that could never have been suspected in the “ugly” theory.
If we generalize the scientific aesthetic in the same way that we generalized the athletic aesthetic, we derive something like this: Beauty in Science is a theory that brings order, simplicity, new insights and consistently correct predictions to a complex, challenging, and previously impossible to understand dataset, and that does so without either manipulating the original data or adding unexplained, unmotivated factors into the calculations to force them to match the observations.
Next Week: Back to Art