Ancient ostrich eggshell beads
In the year 2014, a space capsule named KEO will be launched into orbit by the European Space Agency. Its destination is the planet Earth, 50,000 years from now. Consider it an upgrade to the message-in-a-bottle Golden Record that Carl Sagan strapped to the Voyager spacecraft: on board will be a smorgasboard of humanity: a drop of human blood encased in a diamond, a compendium of human knowledge, photographs of people from “all cultures,” and other vestiges of our civilization). Also on board: a specially-engineered, durable DVD, with pictographic instructions for building a DVD reader. Every member of humanity is invited to imprint a message on this DVD.
Forty one thousand years ago, a group of people lived at a place now called Enkapune Ya Muto in the Maasai language or Twilight Cave. This rock shelter is driven into the side of a 3,000 meter cliff known as the Mau Escarpment, forming one of the walls of Kenya’s Great Rift Valley. Here, forest and savanna merge, and this site, along with other early African habitations, is the crucible of humanity’s prehistory. In an area of only dozens of square meters, blades were flaked, meats charred, and plants littered. Over the next 41,000 years, these artifacts were buried in a silt deposition 5-6 meters deep, as they were joined by the refuse of later peoples, journeymen of the Iron Age, who dribbled ink on a palimpsest invisible to their eyes.
In this ancient place, at the earliest period of habitation, lived an artist engaged in a peculiar industry. The artist would scavenge ostrich shells from the valley and cut the shell fragments into circular beads. These beads, preserved under dust for 41,000 years, look unremarkable save for their abundance. They are yellow and speckled disks, no more than 6 millimeters across, with bore-holes through their centers. Today, there remain more than six hundred of the beads. The beads, useless as tools, beg explanation. They are an unusual kind of material; they mean something. They establish that the artist who made them was a cognitively modern human, and they mark the advent of the Late Stone Age.
If you are reading my contribution to our time capsule, fifty thousand years from now, you may have just seen an aurora in the sky. You may have witnessed a meter-long sphere careening through the magnetosphere, then the planet’s atmosphere; perhaps it has been spotted by a tracking system and found floating in the middle of the South Pacific. Investigation uncovers artifacts stowed inside its hollow casing, technology similar to that found in ancient settlements. A group of people interested in past civilizations attempts to decipher its purpose. By calculating its trajectory and discovering its lack of on-board propulsion, it is clear that it was, in fact, launched 500 centuries ago.
But, as always, why? The group argues about this for some time. One of the members points out after some thought that the civilization that produced the sphere had acquired knowledge of the laws of gravitation, electricity and magnetism, and quantum mechanics. In addition, the sphere is pristine, and its contents have been preserved against the radiation of outer space by a layered metallic casing and vacuum seals. Whatever the meaning of the sphere’s launch and subsequent return, whatever its contents, it has another message for right now: it was planned.
THE ORIGINS OF PLANNING
Today, we are similarly puzzled by the appearance of six hundred spherical capsules underneath the ground, but we have some insight into their meaning. In the Kalahari Desert of Botswana, the !Kung tribespeople continue to make such ostrich eggshell beads. Camps periodically meet and stop to trade beads for beads in a counter-intuitive equilibrium.
The beads have no day-to-day purpose. They belong to a system of exchange known as hxaro (pronounced “schwar-o”), and they represent tokens of friendship. (In the !Kung language, the word gift is synonymous with “ostrich eggshell bead.”) When one !Kung risks starvation, he or she may plead for help from a hxaro tie. When one !Kung flees a territory because of drought, he or she may secure a home in the territory of a hxaro partner. Thus, the ostrich eggshell beads serve a recondite yet essential purpose. They join people together, providing social insurance in times of trouble. To engage in hxaro is to plan for the future.
It is commonly suggested that humans became truly modern when they learned how to manipulate abstract symbols. However, the manipulation of symbols is only one of many innovations that poured out from sites in sub-Saharan Africa tens of thousands of years ago.
Fifty thousand years ago, during the Middle Stone Age, people living at the Klasies River in South Africa hunted seal pups of all sizes. At some point thereafter, all of the pup skeletons in the fossil record are of the same maturity, suggesting that humans were only hunting them at one time of the year, during August to October, a time during which seal pups wash ashore, dying of natural causes. 50,000 years ago, the people of the Klasies River discovered that they could plan their seaside habitation around the period of the year when seal pickings were easiest.
One of the Klasies River Caves, at the very southern tip of Africa, which provide evidence of the behavior of Homo sapiens at our very earliest moments of existence. (John Atherton / Flickr)
Paleo-anthropologists today dub the period in Africa 40-50,000 years ago “the Great Leap Forward.” It is a challenge to describe what happened to the settlements there. All at once, humans developed new tools, new patterns of seasonal migration, new methods of obtaining nourishment; people began to manufacture jewelry and other material symbols, to play games, to make music. The dead were now buried. A package of skills, rituals, and manufactured objects spread across the continent — by word-of-mouth, migration, or trade.
Beyond the challenge of characterizing this shift in survival strategies, it is difficult to discern its impetus. Was there a radical but anatomically inconspicuous change in the human brain? Perhaps the human brain did not change significantly while humans accumulated a cultural patrimony. We may never know. Yet we can assert with confidence that this stratigraphic level, the Late Stone Age, is an age in which human beings became markedly more sophisticated at planning. Humans could now overtly conceptualize the future, and they could engage in activities to minimize future risk or maximize future gain.
In English, the word “time” and the word “tide” are cognates. Before precise chronometry, time and tide were indeed intertwined. A coastal population dependent on fishing would use the tide levels to plan the day. A fishing village’s level of social complexity demanded no finer method. The ancient agrarian civilizations of Babylonia, Egypt, Greece, East Asia, India, and Mesoamerica became expert in the wanderings of the planets and the seasonal variations of the night sky. Calendars were invented, often based on the periodicity of lunar phases.
As civilizations became more dependent on accurate estimation of the season, they moved towards calendars based on the rotation of the Earth around the Sun. The Babylonians used a luni-solar calendar, an embedding of twelve lunar phases into one cycle around the sun. (It is for this reason that the Babylonians constructed a duodecimal number system and, vestigially, why we have twelve hours per half-day.)
The Voyager Golden Record will be within 1.6 light years of the star AC+79 3888 in the Ophiuchus constellation in about 40,000 years.
KEO was originally scheduled to launch in 2003, but was later delayed to 2006, then to 2007/2008, then to 2010/2011, then to 2012, and is currently estimated to launch in 2014.
We now routinely plan one hundred years into the future. Centuries ago our ancestors laid the cornerstones of cathedrals that still undergo construction. We engineer buildings to stand against winds we do not expect for a lifetime.
The connection between upsurges in social complexity and innovations in temporal planning persists. In the 18th century, colonial trade encouraged sea-faring nations to solve the longitude problem, to keep accurate clocks on board ships to anticipate the duration of a voyage. As the telegraph and train brought cities and countries into contact during the 19th century, the Canadian railroad engineer and advocate of universal time Sandford Fleming wrote,
“Lines of telegraph and steam communications are girdling the earth, and all countries are being drawn into one neighborhood — but when men of all races, of all lands are thus brought face to face, what will they find? They will find a great many nations measuring the day by two sets of subdivisions, as if they had recently emerged from barbarism and had not yet learned to count higher than twelve.”
We now routinely plan one hundred years into the future. Centuries ago our ancestors laid the cornerstones of cathedrals that still undergo construction. We engineer buildings to stand against winds we do not expect for a lifetime. Global warming encourages us to plot projections of the mean ambient temperature for the next hundred years and to discontinue the use of pollutants whose atmospheric effects may linger just as long.
And we have begun to plan for even longer. We store plutonium waste with a half-life of 24,100 years. We build seed banks and giant clocks to last millennia. We send time capsules into space which will not return for 2,500 generations. Fifty thousand years after the first cave-dweller consecrated her future in an eggshell bead, we are soon to consecrate another 50,000. Human social complexity is measured by the ability of groups of people to plan jointly for the future.
In KEO, we have begun to think about a more distant future than anyone has thought about before. Whether you are even there to open this, whether you can read this, will really depend on the planning we choose to do now, or choose not to do.