[LEAPSECS] Post-apocalyptic time-keeping story...

Zefram zefram at fysh.org
Mon Nov 4 07:44:41 EST 2013


Michael Spacefalcon wrote:

> If the solar-powered

>"timers" went through periods of not being recharged, where would they

>get their "True Time" from?


They could go into a low-power mode when nearly discharged, maintaining
the time internally but not displaying it until recharged. There's plenty
of precedent for this, ranging from motherboard RTCs (battery powered
when the board is unpowered) to the Ten Thousand Year Clock (display
powered separately from the timekeeper).


>just how much accuracy can one expect from what once were low-end

>consumer cheap quartz oscillators in free-running operation for a few

>centuries?


That's the more interesting issue. A major theme of the story is that
the timers are being treated as canonical, not only in preference to
solar time but also in preference to what amounts to Ephemeris Time.
If they were all to drift relative to physical time, but synchronised
with each other, it's clear that they'd still be accepted as True Time.
But drifting relative to each other probably wouldn't be acceptable:
the story specifically refers to knowing the time down to the second.

Some options: they're near-future tech using chip-scale atomic clocks;
WWV is still operating (itself solar powered); the timers are mutually
synching by wireless mesh networking; no one is wealthy enough to get
two timers in the same place to compare them down to the second.


> (The reference to Fin's uncle etc seems to suggest that a

>century or two post-apocalypse is what the author had in mind.)


Yeah. The references to pre-apocalypse buildings sets an upper limit
of a millennium or so; over decades and centuries concrete will crumble
(with wide variation in the rate depending on composition) and asphalt
roads will be destroyed by plant growth.

Lower limit is set by the mass loss of knowledge: pre-apocalyptic times
are at least a couple of generations removed from living memory.


>I personally find it far more amazing that the "mathers" and "timers"

>(i.e., things that were originally built as cheap throw-away consumer

>gear) can work at all


They're necessarily among the most robust of pre-apocalypse electronic
devices. They may not be the ones built as cheap throw-away gear; they
could be ruggedised for military use, for example. There was no mention
of a superior class of sunblessings, so the single class described must
consist of the most robust of those devices that would be usable at
all post-apocalypse.

-zefram


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