--- Log opened Mon Nov 08 00:00:26 2021
01:36 -!- Llamamoe [~Llamamoe@public-gprs631618.centertel.pl] has joined #hplusroadmap
03:54 -!- spaceangel [~spaceange@ip-89-176-181-220.net.upcbroadband.cz] has joined #hplusroadmap
05:40 < muurkha> happy Frege's birthday
05:43 -!- yashgaroth [~ffffffff@2601:5c4:c780:6aa0::f2f0] has joined #hplusroadmap
05:45 < muurkha> the traditional way to get a layer of glass on the surface of clay vessels is called "glazing" and is significantly less of a pain in the ass than trying to CVD-coat porous substances with silicon :)
05:47 < muurkha> the great downside of glazed fired clay over regular glassware is that it's opaque so it's harder to tell what's going on inside from outside
05:50 < muurkha> clay isn't necessarily an indispensable step, but it's fundamental to all human cyclic fabrication systems for the reason docl says: it's refractory, chemically resistant, and plastic when wet until sintering
05:55 < kanzure> lsneff: attracting billionaire interest doesn't work that way; basically you need to have something and then they just show up. it might sonud weird but try it.
05:57 < kanzure> i don't understand the diamonds
05:57 < muurkha> blast furnaces: largely firebrick, though other refractories can be used (sodium-silicate-based or phosphate).  lost-wax casting: traditionally you stucco the wax with clay, though plaster of paris is a popular alternative nowadays. sand casting: traditionally greensand (sand bonded with a little bentonite) though modern practice also substitutes petrobond (sand bonded with a little tar) and sand 
05:57 < muurkha> bonded with sodium silicate
05:58 < muurkha> the diamond is sort of like the opposite of the TCP/IP bowtie where IP is the knot in the middle, unifying many different physical layers underneath and many different application protocols above
06:00 < muurkha> the tip of the pyramid is your cyclic fabrication system itself: a kilometer-long lunar crawler or whatever.  breaking it apart into subassemblies you go down the pyramid, getting wider in a larger and larger number of subassemblies and subsubassemblies
06:01 < muurkha> but at some point the subassemblies start to diminish in number again.  maybe the crawler has 382508 screws but they're all 20-mm M6 screws and 5-mm M3 screws, for example, and maybe it has thousands of ball bearings that are of only three or four types
06:02 < muurkha> and maybe at the next level down all three types of bearing use the same bearing ball, and maybe the screws and the bearing balls are made from the same type of steel with different heat treatment
06:04 < muurkha> so the pyramid starts getting narrower and narrower until you're resting on some small number of kinds of raw materials, like basalt, clay, and water, say (for an autotrophic selfrep)
06:05 < muurkha> kanzure: does that make sense?
06:07 < kanzure> ok so just an inverted parabola really.
06:08 < muurkha> parabola?  what are the coordinates?
06:08 < kanzure> horizontal being the number of constituent components required, and the vertical being the number of components you can make
06:09 < kanzure> small number of things can be made by a small number of things, the middle can be made by combinations of simple components, and the other end is a small number of highly complex components requiring a few subingredients themselves
06:09 < muurkha> yeah, something like that
06:10 < kanzure> maybe different manufacturing processes need a self-replication factor rating, and then the trick is empirically finding what the cutoff threshold needs to be to make a viable system
06:11 < kanzure> unfortunately the rating can only be computed in the context of the other parts
06:11 < muurkha> Charlie Stross made some characteristically numbskulled comments about this somewhere
06:12 < muurkha> http://www.antipope.org/charlie/blog-static/2010/07/insufficient-data.html
06:13 < kanzure> docl: i think you can make a better pitch than that.
06:13 < muurkha> I mean his conclusions are boneheaded but some of the thought processes are interesting
06:16 < muurkha> given the above example of a lunar crawler held together entirely with M6 and M3 screws, you could surely make a more robust one out of less material if you also used some M20 screws, or if some of the M8 screws were M8-1.0 instead of M8-1.25, or if some of them were Class 8 heat-treated
06:19 < muurkha> so if you take a product of current civilization, say, a cigarette lighter or a ballpoint pen, you find that it is made out of at least ten different materials: maybe two kinds of brass, three structural plastic thermoplastic filled systems, two kinds of steel, one to four kinds of paint, one or two elastomers, plus the actual butane or ink
06:19 < muurkha> and mischmetall in the lighter
06:21 < docl> kanzure: probably so, I'll keep thinking about it
06:22 < docl> was thinking a diamond gives you a visual where it comes to a point at both top and bottom (e.g. brin uses this in his political ramblings) but it's not likely in reality that the curve would be straight edged like a baseball diamond
06:23 < muurkha> from there it's easy to jump to the conclusion that you need a vast diversity of industries to make a cigarette lighter so that you can make all these specialized materials
06:24 < docl> "it is impossible to light a cigarette without 1000 industrial inputs oh no"
06:24 < muurkha> but the truth is that you could probably make the whole thing out of spring steel and butane.  lap some valves instead of using rubber, etc.
06:30 < muurkha> nobody does that because there's no market for a US$300 cigarette lighter that doesn't work as well as a 30¢ Bic
06:30 < muurkha> but it's a question of the economic incentive gradient, not mere feasibility
06:32 < muurkha> on Moon, prices are different
06:38 -!- CryptoDavid [uid14990@id-14990.uxbridge.irccloud.com] has joined #hplusroadmap
06:43 < lsneff> I’m having second thoughts about the diamond idea—there’s a huge number of outputs, more than the number of raw material types
06:46 < docl> it's about the needs for replication, not the potential outputs
06:46 < docl> i.e. where a diamond comes to a point at the bottom the system can replicate
06:48 < lsneff> Ah, right
06:48 < lsneff> I’m trying to think of some plant that looks like a this
06:48 < muurkha> right.  you could build lots of products from the parts the lunar crawler makes that aren't the lunar crawler itself
06:48 < docl> everything in the girth of the diamond is an output, and processes with a wider range of potential outputs can act as terminating nodes for more of the branches
06:48 < lsneff> It’s almost like an inverted tree
06:48 < muurkha> yeah, it's a dag
06:51 < lsneff> dag is a bit broad
07:44 -!- strages [uid11297@helmsley.irccloud.com] has quit [Ping timeout: 256 seconds]
07:48 -!- strages [uid11297@id-11297.helmsley.irccloud.com] has joined #hplusroadmap
08:07 < fenn> .title https://techcrunch.com/2021/11/05/helion-series-e/
08:07 < saxo> Helion secures $2.2B to commercialize fusion energy – TechCrunch
08:11 < fenn> i've been following david kirtley for a while, he does good research
08:17 < maaku> lunar regolith is going to absolutely destroy whatever machinery you put on the surface
08:17 < maaku> much easier to make a sand-crawler on earth first
09:52 < docl> earth first is the idea
10:05 < superkuh> But not "Earth First!".
10:07 < docl> right... although lots of green energy / ecological remediation might be a use case, it's not the main focus
10:29 < maaku> imagine the most abrasive material you can. multiply that by 100x and reduce in size to submicrons so it gets into everything, and that begins to approach lunar dust
10:29 < maaku> there are whole conferences dedicated to the subject of dust mitigation, I believe
10:31 < maaku> One of the reasons apollo missions were only 3 days was that was the approximate MTBF for suits, airlocks, rover parts, etc.
10:40 -!- CryptoDavid [uid14990@id-14990.uxbridge.irccloud.com] has quit [Quit: Connection closed for inactivity]
10:50 < docl> I'm guessing if you put it in a tank with some water it loses its abrasive qualities with time and becomes indistinguishable from regular clay powder. not that this is necessarily practical on the moon.
11:10 -!- darsie [~darsie@84-113-55-200.cable.dynamic.surfer.at] has joined #hplusroadmap
12:10 -!- Codaraxis [~Codaraxis@user/codaraxis] has joined #hplusroadmap
14:41 -!- Llamamoe [~Llamamoe@public-gprs631618.centertel.pl] has quit [Quit: Leaving.]
15:43 -!- spaceangel [~spaceange@ip-89-176-181-220.net.upcbroadband.cz] has quit [Remote host closed the connection]
15:52 -!- srk [~sorki@user/srk] has quit [Ping timeout: 245 seconds]
15:52 -!- srk_ [~sorki@user/srk] has joined #hplusroadmap
15:55 -!- srk_ is now known as srk
16:00 -!- darsie [~darsie@84-113-55-200.cable.dynamic.surfer.at] has quit [Ping timeout: 244 seconds]
20:12 < maaku> docl: I don't think it can be reasonably described as clay powder?
20:13 < maaku> it contains a lot of reduced metals and unusual minerals, shocked into random jagged shapes by impacts, and both microscopic and macroscopic sharp edges aren't worn down by any natural process
20:29 -!- yashgaroth [~ffffffff@2601:5c4:c780:6aa0::f2f0] has quit [Quit: Leaving]
20:44 -!- Netsplit *.net <-> *.split quits: Codaraxis, streety
20:45 -!- Netsplit over, joins: Codaraxis, streety
22:14 < fenn> docl: clay is not just small particles of rock, it's formed through a different process. superheated steam blowing through lava creates thin films that then harden and shatter into microscopic plates. the plates have greater surface area in contact so they tend to stick to each other, hence the stickiness of clay
22:14 < fenn> clay is volcanic ash iirc
22:15 -!- faceface [~faceface@user/faceface] has quit [Remote host closed the connection]
22:17 < fenn> karl schoeder had this idea to use solidified ferrofluids as airlock seals. it could maybe work for other types of seals too. seal leaks? just turn off the magnetic field and let it regenerate its shape
22:17 < fenn> schroeder*
22:18 < fenn> tiny pieces of rock smaller than dust are called "fines" but there isn't really an earth equivalent
22:18 < fenn> you can see something like regolith if you take apart a heavily used bench grinder
22:20 < fenn> acid corrosion tends to sharpen sharp edges so i'm not sure if that will work
22:22 < fenn> you could of course run it through a wind vortex machine for a long time, to tumble the edges off the grains
23:48 -!- darsie [~darsie@84-113-55-200.cable.dynamic.surfer.at] has joined #hplusroadmap
--- Log closed Tue Nov 09 00:00:27 2021