It looks like it’s Indian archaeology day today at The Glittering Eye. One of the fascinating things about the deciphering of unknown ancient scripts is how much of the progress has been the result of the work of amateurs. Egyptian hieroglyphics. Linear B. The Mayan hieroglyphs.
An Indian computer scientist is making progress in something that has puzzled archaeologists for nearly a century:
The Indus civilization, which flourished throughout much of the third millennium B.C., was the most extensive society of its time. At its height, it encompassed an area of more than half a million square miles centered on what is today the India-Pakistan border. Remnants of the Indus have been found as far north as the Himalayas and as far south as Mumbai. It was the earliest known urban culture of the subcontinent and it boasted two large cities, one at Harappa and one at Mohenjo-daro. Yet despite its size and longevity, and despite nearly a century of archaeological investigations, much about the Indus remains shrouded in mystery.
What little we do know has come from archaeological digs that began in the 1920s and continue today. Over the decades, archaeologists have turned up a great many artifacts, including stamp sealings, amulets and small tablets. Many of these artifacts bear what appear to be specimens of writing—engraved figures resembling, among other things, winged horseshoes, spoked wheels, and upright fish. What exactly those symbols might mean, though, remains one of the most famous unsolved riddles in the scholarship of ancient civilizations.
That’s where Rajesh Rao came in:
About 22 years ago, in Hyderabad, India, an eighth-grade student named Rajesh Rao turned the page of a history textbook and first learned about this fascinating civilization and its mysterious script. In the years that followed, Rao’s schooling and profession took him in a different direction—he wound up pursuing computer science, which he teaches today at the University of Washington in Seattle—but he monitored Indus scholarship carefully, keeping tabs on the dozens of failed attempts at making sense of the script. Even as he studied artificial intelligence and robotics, Rao amassed a small library of books and monographs on the Indus script, about 30 of them. On a nearby bookshelf, he also kept the cherished eighth-grade history textbook that introduced him to the Indus.
“It was just amazing to see the number of different ideas people suggested,” he says. Some scholars claimed the writing was a sort of Sumerian script; others situated it in the Dravidian family; still others thought it was related to a language of Easter Island. Rao came to appreciate that this was “probably one of the most challenging problems in terms of ancient history.”
As attempt after attempt failed at deciphering the script, some experts began to lose hope that it could be decoded. In 2004, three scholars argued in a controversial paper that the Indus symbols didn’t have linguistic content at all. Instead, the symbols may have been little more than pictograms representing political or religious figures. The authors went so far as to suggest that the Indus was not a literate civilization at all. For some in the field, the whole quest of trying to find language behind those Indus etchings began to resemble an exercise in futility.
A few years later, Rao entered the fray. Until then, people studying the script were archaeologists, historians, linguists or cryptologists. But Rao decided to coax out the secrets of the Indus script using the tool he knew best—computer science.
Rao and his colleagues compared the degree of randomness, something called conditional entropy, in the Indus glyphs to that in natural language, computer language, naturally occuring patterns, and some artificially created patterns with high and low degrees of randomness. The conditional entropy in the Indus glyphs most closely resemble that found in natural language:
If it looks like a language, and it acts like a language, then it probably is a language, their paper suggests. The findings don’t decipher the script, of course, but they do sharpen our understanding of it, and have lent reassurance to those archaeologists who had been working under the assumption that the Indus script encodes language.
The next step will be to determine if the sequences can be related to grammatical sequences in known natural languages, in all likelihood starting with Dravidian languages like old Tamil or Indo-European languages like early Sanskrit.
It would be interesting to see what their methods made of other puzzling samples, e.g. the Phaistos Disk.
Above: a sample object from the Indus civilization depicting the Lord of the Animals.