Reading List: Longitude and How We Know
We think KNOWING is so easy that we approach the unknowable with suspicion. Longitude by Dava Sobel and William J.H. Andrews is a worthwhile read if only to challenge the certainty of our suppositions. Modern precision is grounded in countless struggles with imprecision.
The truth is that we encounter what is at least difficult to know or even unknowable more often than we realize. The book concludes with a short passage that captures how simple and familiar ideas help us believe we know something about the incomprehensible.
With his marine clocks, John Harrison tested the waters of space-time. He succeeded, against all odds, in using the fourth—temporal—dimension to link points on the three-dimensional globe. He wrested the world’s whereabouts from the stars, and locked the secret in a pocket watch.
We recognize this idea of “testing the water,” but Sobel asks us to apply it to space-time. Few of us have any experience with space-time outside of our favorite Star Trek episode. We’ve never actually seen this temporal dimension but we can imagine it alongside the three-dimensions we know and the recognizable globe those dimensions draw for us. Distant stars had obscured our whereabouts for centuries until something as familiar as a pocket watch made it possible to know one’s location. What we know (the watch, three-dimensional space, and troubled waters) helps us understand what is unknowable (space-time, the fourth dimension and the systems of the universe).
We regularly rely on our imagination to understand the world around us. Our preoccupation with using the simple tools of modern life while dismissing the complexity of their original proposition is dangerous. It threatens our understanding of how essential imagination is to the pursuit of knowledge and our ability to invent the very tools that have captured our attention. The GPS embedded in your car or your smartphone began with John Harrison’s first model for calculating longitude, the H-1. It weighed 75 pounds and sat in a 4ft. x 4ft. x 4ft. cabinet. Accurate enough for the Longitude Board charged with granting the £20,000 award, the H-1 did not satisfy its inventor who had spent five years building it. Harrison knew it could be more precise. And more manageable. Solving the problem of longitude was not enough if the solution was impractical for sailors who needed this information while navigating the open sea. Knowing one’s longitude had alluded sailors and astronomers for hundreds of years, but Harrison seemed to believe finally knowing it was of little value without an easy way to access the data and calculate distance.
His designs continued to evolve until he presented the H-4 nearly 25 years later. The H-4, Harrison’s “sea watch,” finally put the precise measure of time in a device as simple as a pocket watch. The precise measure of longitude was not only knowable in 1760, it was finally easy to use.
The elements of Sobel’s narrative as she tells the longitude story sometimes appear more convenient than real. Longitude undoubtedly only skims the surface of the actual story, but the opportunity to think through the complicated nature of something considered to be so simple today makes the quick read worthwhile. The story makes the sophistication that accompanies innovation just a little more tangible.
It reminded me of a 20th century story of innovation too. In Walter Isaacson’s biography of Steve Jobs, Isaacson reflects on a quote from the very first Apple brochure, “Simplicity is the ultimate sophistication,” and remarks, “Jobs had aimed for the simplicity that comes from conquering complexities, not ignoring them.
Sophisticated knowledge requires us to confront complexity too.