[ExI] Clarification of me and uploading.

spike spike66 at att.net
Fri Oct 22 16:09:45 UTC 2010


> ...On Behalf Of Alan Grimes
> Subject: Re: [ExI] Clarification of me and uploading.
> [I hate my browser]^3

[Sorry to hear]^3

> > Further, mass is needed to interact with the world.  A computer, by 
> > itself with no connection to robot limbs or other 
> > mechanical controls, can not actually do anything...

Cool, progress!  {8-]

Granted, but I am not proposing a system without robot limbs.  Read on.

> His idea is that by reducing the ENTIRE UNIVERSE to 
> computronium, actual physical interactions would become obsolete...

Partly right.  I think of it as *increasing* the entire universe to
computronium, with physical interactions greatly reduced, but not completely
obsolete.  Read on, sir.

> --
> Powers are not rights.

Indeed!  Another topic for another time.  {8-]

Adrian wrote:

>Consider the mass ratio of a computer to the power plant (not battery or
other energy
storage, but energy generation) that powers it.  Might it not be the case
that, even if
optimum computronium becomes available, the majority of the mass might need
to be
devoted to energy harvesting - as in a classic Dyson sphere?

An excellent set of question are raised by this comment.  What is the mass
ratio?  How would one estimate it?  Here's how I would go about it.  Think
of a current technology solar cell and a current technology microprocessor
such as the one used in a phone.  We know a battery with mass of about 20
grams holds a charge to run that processor for about 4 days, so I would
reason that at steady state with those energy densities, a solar cell in
constant full sun of area about 5 cm^2 can run that processor at stead
state.  So could we make or imagine a computronium node with about 5 cm^2 of
solar cell, with the processor and memory on that back of that, along with
perhaps some limbs, a few hundred or so?  So it would be bigger than an
american quarter dollar but not a lot bigger.

I have imagined a computronium node as a disk by the following process:
start out imagining a sphere.  Surface area available for gathering sunlight
is pi*r^2 (not 2*pi*r^2 because we need to take into account the angle of
incident sunlight), and the volume as 4/3*pi*r^3.  The surface available on
a disk for gathering sunlight is pi*r^2, and its volume is pi*r^2*t where t
is the thickness.  Model the limbs however you wish, but I have their
collective mass as a nearly negligible mass with respect to the coin-sized
node.  The disk shape makes better use of the mass.  

So now, you guys who are up to speed on low-power use processors, how much
calculation can be done with a cell-phone class processor?

More later; apparently it is time to be a parent.


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