I’ve been away from blogging for quite some time – mainly to finish a book I was working on. The book is unrelated to particle physics, but follows a course I teach at Harvard, called Primitive Navigation. We explore navigational techniques used by cultures like the Polynesians and Norse, in addition to looking at environmental topics like the origins of ocean currents and global weather systems. While doing research for the book and the course, I found that humans have always been exceedingly clever in making sense of their environments and harnessing this knowledge to journey long distances. I found that the ability of humans to develop sophisticated constructs to bring order to their environment is not limited to the lineage of Western scientific thought but is a more universal trait.
We often think of the roots of science starting with the ancient Greeks, or even further back to the Babylonians. The canonical history is a marriage of mathematics and logic coupled with empirical observation. The story stretches through the Arab translations of works like Euclid’s Elements during the Dark and Middle Ages, through the emergence of the scientific revolution, and culminating in the dizzying heights of modern works like quantum field theory. This is not to say that there weren’t hiccups. Although most scientists would dismiss astrology as quackery, astronomy and astrology were once deeply intertwined from their Western birth in Babylon through the time of Kepler.
I invite you to take a big step back and ponder the following conjecture – that Homo sapiens has always been intrinsically disposed toward scientific thinking. This is perhaps not ‘science’ in the way we view Western science, but it still has the existence of conceptual framework on which to hang and connect observations.
In the process of doing research for the book, I interacted with a number of anthropologists who are studying the navigational schemes of Pacific Islanders. Their work demonstrates the existence of an exceedingly sophisticated ‘toolkit’ of navigational schema that allowed them to travel huge distances across the ocean to find small target islands successfully. Three anthropologists in particular have uncovered some amazing findings: Cathy Pyrek, Rick Feinberg, and Joe Genz.
Most archaeological evidence points to the emergence of long-distance voyaging by a group called the Lapita people, circa 1600 BC from the Bismarck Archipelago, near New Guinea. They built craft capable of sailing into the wind, making jumps of hundreds of miles eastward to locations like Fiji, Tonga, Tahiti and the Marquesas. Even more astonishing was the rapid explosion of voyages of thousands of miles around AD 1000 to Hawaii and the north island of New Zealand.
In order to sail against the wind, one needs to create a sail capable of lift, like a wing and use it in combination with a hull that ‘grabs’ the water as it slices through. The Lapita figured how to harness the complex fluid dynamics involved in lift and used it to their advantage. In the 18th century, Captain James Cook marveled at sophisticated design of the Polynesian voyaging canoes that allowed them to travel at speeds far in excess of Western European vessels. It wasn’t until 1904 that physicist Ludwig Prandtl laid out the theoretical basis for lift in wings, and wasn’t until the 1970’s that this theory was applied to sails.
The clever design of voyaging canoes was only part of the innovations the Pacific Islanders. In order to sail across vast stretches of ocean, they needed viable navigational schema. We don’t have written records from the height of the voyaging period for Polynesians (circa AD 1000), but we do have interviews with modern day practitioners of indigenous navigational techniques that hint at the ways their ancestors crossed large stretches of ocean accurately.
Anthropologists Rick Feinberg and Cathy Pyrek from Kent State have shown how indigenous navigators in eastern Solomon Islands use a ‘navigational tool-kit’, that consists of multiple signs. Stars that are rising or setting close to the horizon form a natural star-compass. Their rising and setting positions allow navigators to find the ‘azimuth’ or compass heading toward a destination island. This requires the navigator to memorize a large number of stars and become familiar with their paths across the sky at different times of the year.
While a star compass may be useful, what does a navigator do during the day or in overcast weather? Another helpful construct is a wind-compass. Winds blowing from different directions have different characteristics. In the eastern Solomons, the trade winds blow from the southeast, and are marked by characteristic ‘trade wind cumulus’ clouds that only grow to heights of roughly 15,000 feet and are then truncated. These winds mark the direction ‘tonga’, or the southeast, which corresponds to the direction of the island cluster of Tonga. Winds from the north arrive during the winter months and are associated with variable, stormy weather.
Steady winds and storm systems can also create ocean swells that act as reliable direction indicators. Often, multiple swells can arise – for example, the Southern Ocean produces a long swell from the south, while trade winds can create shorter wavelength swells from the east. Even if the wind shifts, the swells retain some ‘memory’ of the winds that created them allowing the navigator to maintain a steady heading.
The above tools are useful in maintaining direction under different conditions, but there’s an inherent uncertainty in the position of a vessel, and this uncertainty grows with time. A navigator completing a 200-mile journey may only be able to establish a position to within 20 or 30 miles. Another trick then comes into play: birds. Certain birds, like pelicans and frigate birds will fly some distance out to sea to feed, and then will return to their home islands in the evening. A sailor only has to get to within 30 miles of a target island and then observe land-based birds. The sail is dropped and when the birds fly home in the evening, a course is set.
The navigational toolkit allows for a kind of successive approximation, where the stars, wind, and swells form a rough guide, and the presence and behavior of birds provides the final precision.
A somewhat related but unique tradition is that of wave-piloting in the Marshall Islands. Most of us are familiar with refraction and reflection of waves, whether they’re light or sound waves. Waves on the oceans’ surface are similar, but have some notable differences. First waves in deep-water have a speed that is proportional to the square root of the wavelength. Second, waves in shallow water have a speed that’s proportional to the square root of the depth. This latter relation causes waves to refract in shallow water. When waves get into very shallow water, they’ll often break, losing much, if not all of their energy. On the other hand, waves impinging on a steep cliff that extends underwater will reflect with very little energy lost. Depending on the bathymetry surrounding an island, one can get very different wave patterns produced by the interaction of an incident swell with the island.
Joe Genz from the University of Hawaii studied the tradition of Marshall Island wave piloting for his doctoral thesis. Navigators in the Marshalls have their own language for describing characteristic wave patterns around islands. Nit in kōt is the name given to a crossing pattern of waves on the lee side of an island. If a uniform swell impinges in the eastern shore of an island, the waves passing the north shore will be refracted inside the swell-shadow toward the south and the waves passing the south shore will be refracted into the swell-shadow toward the north. The resulting pattern of crossing waves creates a disturbed region that’s easy to identify at distances beyond which the islands are visible.
In principle, reflected ways should also give clues to the presence of an island. Joe made the acquaintance of one Captain Korent Joel, a native Marshall Islander who was trying to revive the tradition of wave piloting. Joe persuaded Captain Korent to demonstrate his wave piloting technique to a group of oceanographers who deployed a set of sensitive wave buoys. As Captain Korent left the atoll of Arno, he first pointed out the incoming swell from the east, and then the reflected swell off of Arno.
There was only one problem. No one on the boat with Captain Korent could notice the reflections, although the dominant eastern swell was clearly visible. Even the sensitive wave buoys couldn’t detect the presence of the reflected swell. What was going on? Joe wondered whether Captain Korent just thought he should be seeing a reflected swell and was making this up.
In order to put Captain Korent to a sterner test, Joe waited until he (Captain Korent) was taking a nap on in the cabin. Joe instructed the crew to motor some 30 miles to the southwest of Arno to get to a new location. When Captain Korent woke up, Joe told him that he had taken the boat to an undisclosed location and asked him if he could identify the direction to Arno, and the kind of wave patterns he was seeing. Captain Korent was quite certain the Arno was to the northwest, and he was also quite correct! So, he was reading the waves properly after all!
I met Joe in person at a conference of the Association for Social Anthropology in Oceania (ASAO) in Portland Oregon in February 2012. Joe had some videos on his laptop of Captain Korent and shared them with me. I downloaded them to my computer. That evening, I watched the video where Captain Korent was pointing out the reflected swell to Joe on the boat. This was the reflected swell that Joe couldn’t see, and the oceanographer’s buoys couldn’t detect. Joe told me what Captain Korent was saying in Marshallese about the waves. I do some sea kayaking, and I’m often close to the water, and am a bit of an amateur wave-watcher myself.
In my first viewing of the video, I could definitely see the incoming dominant swell from the east. But, by the third or fourth viewing, I could see a weaker reflected swell moving at slight angle against the larger incoming swell. When I compared my observations to what Captain Korent was saying in Marshallese, they agreed completely! By the tenth viewing, I became 100% convinced that Captain Korent was pointing out the reflected swell correctly.
The next day, I called Joe over, along with Cathy Pyrek, who was also attending the ASAO conference. I pulled up the video on my laptop and showed what I saw as the reflected swell. Joe said, “Oh yeah, now I see it”. I turned to Cathy and asked if she really saw it, or I was just convincing them of it, but she said,“It’s definitely there, it’s strange that everyone missed it.”
We still have much to learn about how the human mind operates, but it struck me that Captain Korent’s talents show how we’re capable of picking up very weak signals in the presence of noise. Evidently there is more information on the surface of the ocean than the oceanographer’s buoys were capable of recording. This is perhaps not surprising, but it’s evidence that there are different frameworks of knowledge out there that are effective and are based on empiricism. It may not be Western, but it is a kind of science.
For further reading:
Joeseph Genz, et al., “Wave Navigation in the Marshall Islands,” Oceanography, 22, June 2009, 234-245.
Joseph Genz, “Marshallese Navigation and Voyaging: Re-learning and Reviving Indigenous Knowledge of the Ocean,” (PhD diss., University of Hawaii, 2008)
John Huth, The Lost Art of Finding Our Way, (Belknap Press, Cambridge MA, 2013).