[extropy-chat] Dark matter and ET

Dan Clemmensen dgc at cox.net
Sun Jul 17 16:47:37 UTC 2005


The Avantguardian wrote:

>--- Alfio Puglisi <puglisi at arcetri.astro.it> wrote:
>
>  
>
>>On Sat, 16 Jul 2005, The Avantguardian wrote:
>>
>>    
>>
>>>Well, I am not sure what the the theoretical or
>>>      
>>>
>>real
>>    
>>
>>>limits on Moore's Law might be but it will take a
>>>      
>>>
>>long
>>    
>>
>>>time to catch up to biology. As far as I, as a
>>>biologist, am concerned, DNA IS computronium at a
>>>staggering information capacity/density of 340
>>>exa-bytes (EB = 10^18 bytes) per cubic centimeter.
>>>Just add water. :)
>>>      
>>>
>>Does this figure only takes into account the DNA
>>molecule, or all the
>>supporting proteins around as well? The minimum unit
>>would be something
>>like a small cell, or maybe a nucleus.
>>    
>>
>
>No, it is just the figure for B-DNA with its hydration
>spine. It assumes it is maximally packed in a volume.
>This is of course multiple strands. To have all that
>info on a single strand would take somewhat more
>volume due to limited tensile strength although DNA is
>incredibly flexible. Even in a normal human cell
>nucleus with two copies of every chromosome, there is
>1.6 gigabytes of info packed into 6.5 X 10^-11 cubic
>centimeters, that comes to a density of a paltry 25
>exabytes per cubic centimeter. But I wasn't talking
>about a cell, I was talking about DNA as a
>computational medium in general. Naked DNA in solution
>has been used to solve the "traveling salesman
>problem". Feel free to google for refs.
>
>Ciaou. :)
> 
>
>  
>
A computing system needs storage, logic, and infrastructure. An
efficient system maximizes some computing metric with respect to
mass.

I'm assuming that an SI is a computing system.

Our solar system's existing intelligent computing system is an
evolved system that does not yet have much ability to  direct
its own further design, This is another way of saying that
our singularity has not yet occurred. Our evolved system makes
use of DNA for storage and a protein-based, chemistry-driven
nanotechnology for logic and top-level infrastructure. It is an
amazing achievement given no intelligent design, but it is horribly
inefficient at the system level. Almost the entire available mass of the
system is concentrated in the sun, and is unused except as the
first stage of a horribly inefficient power source for the computing
elements. Almost all of the power is lost to space. Of the trivial
percentage that reaches Earth, almost all is re-radiated to space 
immediately,
without effect. Of the tiny percentage that is captured in bio-systems, 
almost
all is used to build plants, and only a tiny percentage of this biomass will
ultimately be used to feed humans. Of the part used to feed humans, almost
all is used to build and power infrastructure rather than to support
computation.

I think an SI will be able to make a few improvements. I think the logical
extrapolation is to a system that has converted its mass into efficient
computronium. My guess is that nanomechanical systems will be the
most efficient.





More information about the extropy-chat mailing list