[ExI] Why space tech isn't cutting edge

[spike]

>... On Behalf Of Adrian Tymes
Subject: Re: [ExI] Why space tech isn't cutting edge

On Mon, Nov 19, 2012 at 9:22 AM, spike <spike66 at att.net> wrote:
>>... Any shielding that is light enough to be carried into space creates a
shower of secondary particles when hit with a sufficiently energetic cosmic
ray...

>...Composite armor, just like tanks use.  Outer layer converts massive
attacks into a spray of smaller attacks.  Inner layer optimized to stop a
bunch of smaller attacks...

Ja most current research in that field goes that way.  The problem is that
cosmic rays have such high energy we are lucky we have both an atmosphere
and a magnetic field around us.  A long time ago I did a calculation to
estimate the lead shielding equivalent of an atmosphere, and as I vaguely
recall it was substantial, on the order of a couple of feet of lead.  I
don't recall the answer, but I do recall concluding it is not a practical
means of protecting electronics.

>>... Recall also that it would need to be shielded from all directions, and
that to stop a 
> cosmic particle would take a huge block of lead.

>...Not that huge, surely?  Considering how tiny CPUs are, and thus the tiny
volume that would need protection...

You hit upon a promising approach: figure out a way to do massive
redundancy, so that the RISEU errors can be outvoted by several parallel
processors.  This is done now to some extent.  We have a control system that
uses three parallel processors.  The output is not used unless two
processors agree on an answer.


> ...  If you need any heavy-duty space-calculations, 
> the way to go is to send the data to the deck, have the super-computers
calculate it and send it back up.

>...So how, eventually, do we get sentient AIs - that run on computer chips,
or some other computing hardware - floating around in space and able to
munch asteroids (at first, then eventually planets) to make more hardware
for themselves?
_______________________________________________

Good question.  I am not convinced we will never find a way to make these
smaller processors work in an EM noisy environment.  We will solve that
eventually methinks.

We already have some processors that will work in space, just not the really
high powered ones.  All is not lost however, for we have the option of
boring a hole into an asteroid or planet surface and having the deep
thinking go on down there, using a super-small featured modern processor
which does not turn on until the tunnel is finished, so that it has a couple
meters of rock shielding everywhere.  Then the surface robots would have the
slower more robust processors getting instructions from the guy down in the
hole.