From: Gary Coffman
Newsgroups: rec.crafts.metalworking

You're implicitly assuming that to replicate a part you need an identical
part on hand as a template. But that's not a requirement. All you really
need is a print.

Of course all you need is a non-self-replicating print, and a
non-self-replicating filing cabinet to keep it in. Do you want to use the lathe
to build a paper mill so you can make the print, and the mill to build a sheet
metal shear so you can file the print, or do you wan't to simplify, simplify,
without cheating.

The only self-replicating thing about a file cabinet full of prints is mildew.

For your postulated Mars machine shop, the mass of prints (most likely
CAD files) is a lot less than the mass of unnecessarily duplicated machines.
Payload mass fraction is *the* critical limit on space flight.


I understand this but explorers are not computers. It takes five minutes to
learn how to repair a bent feed screw and a lifetime to get it really right. It
takes five months just to familarize yourself with the CAD system, the
directory tree, and the contents.

Take out a working or broken part. Clamp it in the obvious way. See what's
needed for the final cut that gives you what's in the chuck right now. Work
backwards. Get stock. Perform first through final operations. Install repaired
part or get on with building new machine.

?

Seems to me you should be trying to discover the fewest number of
machines necessary to replicate a machine shop, given full sets of
plans for all the machines to be produced. I don't think you'd find it
necessary to have identical pairs of any machine tool in order to do
that.


That's a good problem, but I already gave the specification for a universal
machine shop: one that can make useful products, anything you'd like. Except
usually this universality does not include the ability to make each part of
everything in the shop, as one cannot sell such an unauthorized repair part at
full price. So by extending the definition of universality to uneconomic
production, we find among other things that this system is sefl-replicating.

When you're on Mars, you don't hire someone to dig a hole in the ground so you
can take a poop. You cover your own tracks. There's no money planned for Mars,
is there? This is an economy in which productivity is of survival value and
explorers are highly productive people who can surve nearly anything.. Who
cares who pays for what?

You're going to charge your trail buddy hospital rates for fixing his arm when
you're the hospital and he can't make it to the next one without your help? And
then bill him and work out a payment plan? A simple Thank You is enough for me.
Then we move on.

We have about 168 currencies. Even four is too many. One, two, or ideally three
is actually the definition of currency. A traingle is stable. A frame
collapses. So does anything larger.

Now that money isn't backed by gold, we can go to three world currencies any
time. Rather than business, government, and consumer money, we'll probably end
up with Northern Money, Southern Money, Eastern and Western Money, which is
already still too many. We tried for one and ended up with 168. I say stop
trying for one. Try for two, and get 25, each of whom has a one or the other
opinion. Try for three, and get three. Everyone in the industry knows why
there's no point in trying for four. It's not as unstable as 168, but they do
know it isn't stable. Three or fewer is stable.



Yours,

Doug Goncz (at aol dot com)
Replikon Research

Read the RIAA Clean Slate Program Affidavit and Description at
http://www.riaa.org/
I will be signing an amended Affidavit soon.