Noloben glyphs & D'ni numerals
The D’ni numerical system can be said to use a complicated form of base 5. To form the number 5 (or 10 in base 5), the symbol is turned on 90° to the right. To form the number 6 (11 in base 5) that symbol is combined with the symbol for 1. Because of this ‘right-turning’ process, D’ni numerals actually consist of 25 separate symbols (including “0”), and it is only necessary to place two of those symbols side-by-side (as we usually to with “11”, for example) in order to form numbers of 25 and above, which would usually only be a feature of base 25. As such, it is properly described as a base-25 system, although tracing its roots in a base 5 system is important for our purposes here.
The set of glyphs which I have designated as Esher’s clearly follow the same base 5 system. Numbers 1-4 are formed by a one or two vertical lines, combined with one or two horizontal lines. the number 5 is formed by a circle, which is then combined with the glyphs for 1-4 to form the numbers 6-9. Although we do not see how the system progresses beyond the number 15, it is safe to assume that the three-circle glyph will be combined with those of 1-4 to form 16-19, and the number 20 will be a four-circle glyph. Obviously, a less efficient method than that employed by D’ni numerals.
The glyphs inside the laboratory, then, are surely the product of someone used to thinking in base 5 terms, as Esher would be. They are also an attempt to capture the same elegance of base-25 numerals that the D’ni numerals do. Why he felt the need to use these glyphs, which would be so easy for someone from D’ni to understand, is a mystery. The Bahro would have no more chance of understanding the D’ni numerals than those of Esher, perhaps even less. It may tell us something about Esher’s mind that he sought to needlessly recreate a numerical system which worked perfectly well, in order to keep the entrance to his laboratory secret from creatures which would understand neither system. That his new system is so clumsy and inefficient might also be considered instructive.
(The official Myst V Guide observes, on the contrary, that these glyphs are in fact the Bahro’s numerical system, rather than Esher’s.)
If you’re using Mac OS X and want help creating really big numbers, you might like to check check out Rivenumerator or my own D’ni calculator widget (Mac OS X 10.4 only). Try this on for size:
Thanks to Ingmar Ohlsson for adjusting the gamma!