[extropy-chat] Worldwide SOS system

Eugen Leitl eugen at leitl.org
Wed Oct 5 09:48:43 UTC 2005

On Tue, Oct 04, 2005 at 10:09:33PM -0700, spike wrote:

> Sure.  But radios require batteries that 
> might be old and fail when needed most.  And 

No, radios don't need batteries. They need energy.
There are sealed LED lights with build-in solenoid and permanent
magnet which will shine for 15 min after a brief shaking.

There are portable radios with hand cranks.

There are amorphous photovoltaics battery chargers.
A flexible PV foil rolled out and shined upon by
the sun for 15 minutes will easily get you a GPS
position fix and a few packets emergency transmission.

> you need to be close to a receiver for a 
> radio to do any good.  Your invention 

Only for very large values of close (like 5 billion miles).
It is a piece of cake to reach a bird 200 km high passing overhead.
I think there's a specific discipline for HAMs how far
they can come with a given energy budget. Ditto WiFi shootouts.

> could be kept in a sealed can indefinitely.

How many of you have a working mobile phone right now?
Eugen* Leitl <a href="http://leitl.org">leitl</a>
ICBM: 48.07100, 11.36820            http://www.leitl.org
8B29F6BE: 099D 78BA 2FD3 B014 B08A  7779 75B0 2443 8B29 F6BE
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