[HN Gopher] Kinematic Self-Replicating Machines (2004)
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       Kinematic Self-Replicating Machines (2004)
        
       Author : ramboldio
       Score  : 58 points
       Date   : 2021-04-17 14:47 UTC (8 hours ago)
        
 (HTM) web link (www.molecularassembler.com)
 (TXT) w3m dump (www.molecularassembler.com)
        
       | smlckz wrote:
       | Have we humans been able to make artificial physical self-
       | replicating machines? Is it feasible to make such machines?
        
         | ansible wrote:
         | Well, there are degrees of "artificial".
         | 
         | Years ago, we spliced an insulin producing gene into a
         | bacteria's DNA:
         | 
         | https://www.nlm.nih.gov/exhibition/fromdnatobeer/exhibition-...
         | 
         | This is taking a naturally occurring bacteria, and modifying it
         | slightly. We are using the bacteria's existing protein
         | production infrastructure to produce a peptide hormone.
         | 
         | Check out how a ribosome works:
         | 
         | https://www.youtube.com/watch?v=morl5e-jBNk
         | 
         | It is, in some sense, a programmable robot arm that assembles
         | structures from parts.
         | 
         | As we have gotten better at understanding how these mechanisms
         | work, we can tweak things further. We can imagine many
         | directions for this to go in. Not just producing proteins with
         | existing amino acids, but having the bacteria produce new ones
         | with interesting properties.
         | 
         | We could eventually be able to produce a wide array of
         | chemicals, and not just organic compounds. Though the range of
         | things that can be produced is still limited.
         | 
         | The main thrust of molecular nanotechnology is to leave behind
         | the protein synthesis that biological life uses, and instead be
         | able to produce arbitrary structures from arbitrary atoms.
         | 
         | This is a difficult and ambitious goal, but one that is
         | imminently achievable.
        
         | mLuby wrote:
         | No, it's never been done.* While factories are built all the
         | time, they have never been built entirely from their own
         | products _and_ without human labor as an essential ingredient
         | (a  "closed" manufacturing process).
         | 
         | There's an economic reason for this: the _constraints_ that
         | make a factory  "self-replicating" mostly make things more
         | difficult/expensive; they're only beneficial when operating in
         | a human-hostile area disconnected from existing supply chains,
         | so it's always been better to use open-loop factories + human
         | labor to make products quicker, cheaper, and of higher quality
         | than a self-replicator would. Space industrialization is where
         | self-replicators will be exceptionally useful.
         | 
         | These are the key functions of a truly closed-loop self-
         | replicating factory:
         | 
         | 1. collect energy
         | 
         | 2. use energy to collect matter.
         | 
         | 3. use energy and matter to create parts.
         | 
         | 4. use energy to assemble parts.
         | 
         | For example, consider a water-powered saw mill, made of wood
         | with some metal "vitamins":
         | 
         | 1. Wooden water wheels collect energy from flowing rivers.
         | 
         | 2. Humans use wood/metal saws to cut trees, and wooden
         | rollers/sleds and transport them to the mill.
         | 
         | 3. The mill's saws, drills, and lathes turn the tree trunks
         | into useful wooden parts.
         | 
         | 4. Humans move wood parts from station to station in the mill
         | and can assemble another mill from the boards, dowels, and a
         | few metal saw blade/drill bit "vitamins."
         | 
         | Could you replace the humans with logging robots, and use robot
         | arms to move things inside the mill? Sure, but humans are so
         | much better suited for these tasks, and now your humble saw
         | mill has to be able to create, power, and control these robots
         | in order to be closed-loop.
         | 
         | *Yes clever HN, you can get all pedantic about biological self-
         | replicators, self-assemblers, and nano-bots, but you're just
         | muddying the waters. We haven't ever managed a von Neumann-
         | style "clanking automaton" self-replicator.
         | 
         | P.S. don't worry about rampancy--there are physical limits that
         | make sci-fi's Grey Goo floods impossible.
        
         | jpm_sd wrote:
         | This was published in 2004 and was highly speculative at the
         | time. We are still a long, long way from the Diamond Age
         | fantasy of self assembling nanotech.
         | 
         | Recent work in this area seems to mostly involve modding 3D
         | printers to try and integrate conductive materials (basic
         | circuits) into plastic structures.
         | 
         | Example:
         | 
         | https://3dprintingindustry.com/news/botfactory-to-develop-u-...
        
         | science4sail wrote:
         | What do you define as an "artificial physical self-replicating
         | machine"?
         | 
         | A genetically engineered bacterium is a self-replicating
         | machine created via artificial means that exists to effect some
         | purpose in the physical world.
        
           | smlckz wrote:
           | - ''Artificial'': not naturally occuring, also not a
           | "clone"/"fork" of something natural.
           | 
           | - ''Physical'': not software simulation, virtual; "exist" in
           | the same world we live in.
           | 
           | If my original terminology is insufficient or ambiguous,
           | please suggest better terms.
        
           | science4sail wrote:
           | For that matter, the Earth has _already_ had a grey goo
           | ecological disaster:
           | https://en.wikipedia.org/wiki/Great_Oxidation_Event
        
         | choeger wrote:
         | I have three of them at home. They're easy to make but
         | relatively high maintenance. Because of this, I try to make
         | sure that they learn self-maintenance before self-replication.
         | Let's see how that plays out.
        
           | umvi wrote:
           | I would argue that "life" isn't "artificial" i.e. manmade
        
             | emteycz wrote:
             | Agreed on humans, though I wonder where is the line between
             | artificial and natural life? Large portion of genome
             | modified? Synthetic cells? Synthetic cells without any
             | natural cellular components?
        
         | phreeza wrote:
         | I guess it depends on your definition. I can think of many
         | examples that are self replicating in some sense, but probably
         | not in the same way as a bacterium.
         | 
         | A 19th century machine shop is probably capable of self-
         | replicating, with metal as an input and a human 'catalyst'.
         | 
         | A crystal is self replicating in a way.
         | 
         | A computer virus and a meme.
        
       | plutonorm wrote:
       | Has anyone tried evolving small shaped block to self assemble
       | when you shake them together? I'm thinking of SLA 3D printing the
       | shapes in various materials to create a functional component by
       | simply shaking everything together.
       | 
       | Has this been thought about?
        
         | phreeza wrote:
         | I would argue that a self-replicating machine could be a slight
         | modification of this idea. Print some blocks and put them in a
         | container and shake them. Then come up with some structure,
         | made up of these blocks, that will cause a copy of itself to
         | emerge when shaking, that would have never or extremely rarely
         | occurred if the parent structure had not been present.
        
         | sanity31415 wrote:
         | > Has this been thought about?
         | 
         | I'm not aware of artificial examples but this is essentially
         | how biology works at the protein level - so it does work at
         | least at the molecular scale.
         | 
         | In principle it should also work at larger scales although it
         | would probably be _much_ slower, molecules jiggle very quickly.
         | 
         | Programmable magnets (aka "polymagnets") may be applicable to
         | doing it at a larger scale.
        
         | haffi112 wrote:
         | Check this out: https://www.youtube.com/watch?v=X-8MP7g8XOE
        
         | germinalphrase wrote:
         | https://rosieresearch.com/self-assembling-bricks/
        
       | darepublic wrote:
       | Step 1, get the Boston dynamic robots working on the assembly
       | lines of their own factories
        
       | robbrown451 wrote:
       | This is something that explores current things (3d printers, CNC
       | plywood cutters, etc) that could gradually play larger and larger
       | roles in the fabrication of identical -- or better yet, identical
       | with improvements -- copies of themselves.
       | https://www.youtube.com/watch?v=l4tYIX_QJ2Q
       | 
       | This will most certainly happen gradually, and will probably
       | involve a whole cluster of machines. For instance, a robot arm, a
       | 3d printer, and a bunch of jigs and other devices, which together
       | can make parts of themselves or play a role in assembly.
        
       | JoeDaDude wrote:
       | There must be some demand for this book. You can read it online
       | for free or buy a used copy on Amazon for >$300!!
        
       | scop wrote:
       | Here's an honest question that I've pondered occasionally,
       | without really spending the time to research an answer. Not sure
       | if this is biology, chemistry, etc, but would appreciate any
       | insights HN readers may have:
       | 
       | How did replication develop in nature? Granted some cells popped
       | into existence as some point, do we have any insights into
       | when/how cell replication became a thing?
        
         | EvanAnderson wrote:
         | I'd look into autocatalytic sets. From an origin-of-life
         | perspective it's a compelling idea to me.
        
           | hallgrim wrote:
           | Exactly! One aspect to remember is that once you have a self
           | --replicating mechanism, by the nature of it, the replicating
           | parts are becoming more widespread. In other words, small
           | effects with larg, self--reinforcing consequences.
        
         | robbrown451 wrote:
         | Replication has many shades of gray.
         | 
         | Does a fire self-replicate? How about a prion?
         | 
         | Somewhere in between would be self-catalyzing chemical
         | reactions. It's not that hard to imagine how such things could
         | eventually evolve into what we call "life", with no clear line
         | between non-living and living.
        
       | phreeza wrote:
       | Reading through this book a bit I found a mention of penrose
       | block replicators, and through that found this video from the
       | early 60s. Not really a replicator in an real sense, but still a
       | neat demonstration: https://youtu.be/hQ6T_TY3JA4
        
       | [deleted]
        
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