Diaspora (novel) - Polis Time, Delta, and Perception

Polis Time, Delta, and Perception

For internal dating and time standards the polises use CST (Coalition Standard Time), measured in tau elapsed since the adoption of the system on January 1, 2065 (UT). The novel begins at CST date 23 387 025 000 000. CST defines one tau as the amount of time in which a polis citizen can experience the passage of one second of subjective time; this elastic value changes with improvements in polis hardware. At the period of the novel a polis citizen's mind can operate at a maximum speed of about eight hundred times that of a flesher's mind, so 1 tau equals approximately 1/800 sec.

Nothing compels citizens to experience time at such a high rate; they can equally choose to "rush", meaning to experience consciousness at a speed slower than the polis hardware can maintain. Hence citizens could experience consciousness at the same speed as a human flesher would, or slower, or even freeze their conscious state for a set time or until a previously determined event occurs. Egan suggests that some citizens have opted to experience consciousness so slowly that they can witness continental drift and geological erosion.

The polises measure distance, another arbitrary value within their virtual scapes, in "delta", which Egan does not fully explain, although the glossary indicates that citizen's icons are generally about 2 delta high.

Almost all polis citizens, except for those who specifically elect otherwise, experience the world through two sensory modalities: Linear and Gestalt, which Egan describes as distant descendants of hearing and seeing, respectively. Linear conveys information quantitatively, as a string or strings of information formulated with a language hardwired into the mind of almost all Citizens. Citizens may "speak" to one another in Linear by sending streams of data back and forth, from mind to mind — either private conversations carried on between a specific subset of intended participants, or public announcements accessible to all involved in a conversation or otherwise "listening in".

Gestalt conveys information qualitatively, and data sent or received about anything arrives all at once for interpretation by the mind of the Citizen in all its aspects simultaneously, resulting in an experience of immediacy. A citizen need not consciously consider the information sent (as in Linear): Gestalt operates rather entirely or almost entirely subconsciously. Citizens use Gestalt to create icons or for themselves — "visual" representations within Scapes (Gestalt "areas" or "spaces"). Citizens also use Gestalt to convey Tags — packages of information described as like an odour or essence, which any other Citizens within a range of several delta (or who happen to "read" for specific Tags) can gather. Each Citizen has a unique Tag which identifies them as a particular person, regardless of their other appearances, and citizens may emit Tags for other purposes as well, as when Citizens need to convey and understand arbitrary information instantly. Early in the novel, for instance, Yatima learns about an asteroid in the real world by reading its tags subconsciously, which inform ver instinctively about its properties such as mass, velocity, rotation, composition, emission spectra, and other such data discernible to the Coalition's satellite network. Later on, however, on Earth, when ve and Inoshiro inhabit derelict Gleisner bodies, Yatima must remind verself that Fleshers are real people, even though they lack tags identifying themselves as such.