Path: utzoo!mnetor!uunet!mcvax!ukc!stc!idec!camcon!mb
From: mb@camcon.uucp (Mike Bell)
Newsgroups: sci.electronics
Subject: Re: electronic time capsule
Message-ID: <1278@titan.camcon.uucp>
Date: 1 Mar 88 11:11:41 GMT
References: <3a56593d.44e6@apollo.uucp>
Organization: Cambridge Consultants Ltd., Cambridge, UK
Lines: 26

A few thoughts:

using solar power may be a problem.  Within a hundred years grass grows,
soil is eroded or deposited.  Ensuring that a solar collector can still
pick up enough light (and is not totally eroded) may be difficult.  I
guess some remoter sites may be OK assuming no global changes in the
weather.

Other sources of power: 
    thermal (cooling/heating due to day/night)? differential cooling/heating
    rate provides temperature difference = work
    nuclear (not very practical for DIY).
    geo-thermal (dig a deep hole?)

Timing: 
    thermal changes with day/night? with season? used to drive counter?
    changes in direction of the earth's magnetic field as a trigger? 
    cessation of a radio signal (eg. standard time signal) enables transmitter?
    changes in gravity? (eg. lunar/planetary effects)

Any thoughts as to what frequency/message to transmit?

-- 
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