With the exception of the Mayan system, whose zero glyph never left the Americas, ours is the only one known to have a numeral for zero. Babylonians had a mark for nothingness, say some accounts ...

which appeared on Mesoamerican carvings as early as 36 B.C. (Zero didn't appear in Western Europe until the 12th century.) As with many early glyph-related discoveries, serendipity may have played ...