Two Birds With One Stone
I want to relate a story I once heard about archaeology. It is a perfect example of what Martin Gardner calls an Aha! moment. Like all Aha! moments, it’s interesting for the moment of inspiration, but this particular story sticks with me because it has twice the payoff.
The subject is archaeology, and specifically an unexplained class of Mesolithic artifacts, which can be found littering Eurasia, from France to Indonesia. They are flat, chipped stones, about the size of a dinner plate, and varying in size about as much as dinner plates do, maybe eight to twelve inches across. They’re not quite round, but more like a fat teardrop or almond shape, with a broad point jutting out at the edge. And nobody knew what they were for.
More than anything else, they resembled some kind of chopper, an adaptation of the stone hand axe to a particular purpose requiring a point. But what was it made to chop? It was meant for a specific purpose; by the Mesolithic era, people were shaping specialized tools for specialized tasks instead of settling for one all-purpose chopper. The disc was too large to use comfortably as a cutting tool; it was heavier than more generalized hand axes, large and heavy enough to wobble uncomfortably in the hand for tasks like slicing meat and skin. Yet it was also too thin to work well as a heavy chopper for something like wood, prone to snap under the strain. Besides, specialized tools had already been identified for these functions, and, compared to the large quantity of faultless stone necessary for the teardrop tools, much easier and cheaper to produce. The relative effort required to make one of these awkward choppers was especially difficult to explain given how many could be found; stone age users would not simply discard such stones, but continue to reuse them, possibly reshaping them as smaller tools as they wore or broke. Whatever the fat teardrop was meant to do, it was something archaeologists hadn’t yet realized our distant ancestors did at all. It was a tantalizing problem: figure out what the tool could do well, and we’d know something entirely new about stone age people.
Like many archaeologists before her, Eileen O’Brien had a collection of modern reconstructions in various sizes and shapes—the originals being too valuable to chip or break in use—and tested them in a trial-and-error fashion, using them on whatever tasks he could think up: splitting branches, stripping pith from grasses, smashing grain, gouging logs, scraping clay from a riverbed, whatever. The teardrop stones were not especially suited to anything she came up with.
She was literally turning one over in her hands, niggling at the question, while inspiration struck via the television: the set was tuned to the Summer Olympics, and the discus throw came on. And she had to wonder…
She employed two students on the track team to test her theory. Thrown as a discus, the teardrop flew in a low arc, tipping as it spun, so that it struck the ground vertically…point first. Repeated throws ended up point-first forty-two out of forty-five attempts, traveling 100 feet within two yards of the target. Ta-dah! Ancient mystery solved: the teardrop stones were missile weapons, probably used for hunting before spears and arrows replaced them. So many could be found because prehistoric hunters kept losing them in the underbrush. Others had suggested the stones were missiles before, but the theory got no traction, because the stones threw badly. The discus-throw inspiration did the trick.
The best part about this story is that the student simultaneously solved another ancient mystery: why the discus throw was part of the Olympics. Although the modern Olympics include a number of sports for sport’s sake—figure skating, the parallel bars, curling—the original Olympic events were all skills of the hunter and warrior: running, jumping, wrestling, spear-throwing. The discus seemed out of place in classical Olympic competition. The sudden insight simultaneously made sense of both previously inexplicable artifacts and previously inexplicable traditions, from two subjects that seemed to have nothing in common.