Can robot or a device be made that, given the requisite resources, could construct and assemble a functional copy of itself?
To entertain this hypothesis further, let’s add a set of explicit constraints or expectations:
- The copy must structurally match the original device as is realistically possible
- The device must be able to manufacture at least one copy of itself
- The overall replication process should sustain itself for an indefinite amount of iterations
- The device must not repurpose its own parts as parts for its copy
- The device must not peform any task other than replicating itself and preserving itself to be able to replicate
- The device may sustain damages of repairable or non-repairable nature as long as it obeys constraints 1 and 2
- The device may take as much time and resources as it needs to construct its copy as long as both remain finite
- The device may make use of essential external resources like electricity and cooling to sustain itself as long as its able to accommodate its copy to do the same
Can reproduction be emulated mechanically while obeying all the constraints above or is there a fundamental limitation stopping us from realising this concept? If so, what is it?
The RepRap project sorta hit some of your points. It was more about establishing and spreading 3D printers. Evangelizing them. One printer would print all the plastic parts for to make another 3d printer. This could then be given away or sold. Things like screws, rods, motors, and controllers were “vitamins” that need to be added to make the printer. Obviously people were doing the assembly not the printers. They also violated your rule #5 because they could do tasks besides replicating.
My second printer was a Prusa MK3S+. It’s heritage came out of RepRap and a lot of its parts were 3d printed.
Im just thinking life. Hasnt stopped reassembling itself since it’s origin.
Yes, theoretically of course it is.
Even practically it seems, they are all over the place.
They are not. Realistically this is not possible. And may never be.
Complexity is a real problem here. The more different things you want your machine to do, the more human intervention is necessary.
Let’s give this idea the best chance at success and say it’s raw materials and simple components are available to it. Basic fasteners, copper wire, sheet metal, etc.
This robot will undoubtedly have a motor, which would require a bunch of copper wire wound around a magnet, and assembled in a ring. This task is already done by robots. At least, the winding part is. The assembly is too, but it’s a different robot. And let’s say there’s even a robot that can transport the wound magnets to the assembly robot. Such robots exist at least, this wouldn’t be logistically efficient in this particular process but we’re building a self replicating automaton here, sacrifices are necessary.
Anyway this one task requires at least 3 robots AND at present, the raw materials are being initially fed by a human. The magnets might come from a hopper but the copper wire is an issue. Let’s say even THAT is surmountable.
The amount of floor space required for the process is probably something like 300 square feet. Just this process alone. Just to make a single type of electromagnet. We haven’t built the housing, inserted the drive shaft, or any of the other required bits. just the electromagnet.
To make all the parts of a thing that a robot requires is going to be about the size of a factory. and that’s assuming raw materials and basic bits are made somewhere else.
And even if you fully automate a factory, and it can make everything it needs to replicate itself, different machines would be needed to install them all somewhere.
You’re thinking “but 3D printers!”
Stop. No. Just… No. are not that powerful. To be clear, a single metal 3D printer that’s even half as capable as some people have been lead to believe they are could replace about 20 of the highest paid employees in my factory. They just don’t work as well in industry as people seem to think. And that’s printing in a single material. When you try to say, print a magnet with copper wire wrapped around it, you find very quickly that a: this isn’t possible with the current technology, and even if it were, b, the durability just isn’t there. It might be hard, it might be the right amount of brittle, but it doesn’t withstand wear the way you’d expect for something with those properties.
My response was a bit tongue in cheek, I was hinting at Cells.
So theoretically it’s absolutely possible, it exists already.
You could even see humanity as a (not human created but still existing) a form of self replicating machinery.
For a man-built one, you might want to check out Dr Drexlers book Engines of creation (or is it Nanomachines), where he makes the claim that it is indeed possible. He lays out the theoretical math & physics to create APM, atomically precise manufacturing, and that machinery would indeed be able to create a perfect copy of itself.
The question was about theoretical possibility - practical limitations of present-day tech are irrelevant. OP also didn’t put any constraints on how big, heavy or complex the robot would have to be, or if it has to be able to do anything else besides make more of itself. Even if the machinery it has to contain occupies a city block, that’s okay.
Fire can make more of itself if provided with the required resources, but that’s quite chemical.
Sand makes more of itself if it’s provided with rocks and agitation. Ie wind blown sand make more sand as it erodes rocks.
Sand as a self-replicating device sounds too weird to me but it surprising does tick all the boxes.
Now that I think more about it, that’s actually ingenious! I wish I could upvote you tenfold!
I’m glad you like it!
I think the main obstacle is finding the energy to do this. All of the energy that is accessible to us on Earth comes from the Sun, in one way or another (deep sea critters notwithstanding). If this robot can die, which it would have to for this to be indefinite, then it’s possible (eventually it would run out of iron, technically) if it could recycle old parts.
Ofc, a fossil fueled process is not indefinite, it would have to use a combination of clean energy to get through all the unique challenges of each method.
Honestly, this is kind of a first principles thermodynamics problem that applies to humanity in a similar way, one we are not answering with sustainability in mind… No way around the Laws of Thermo!
Mitosis, if cells classify as mechanical
3 The overall replication process should sustain itself for an indefinite amount of iterations
Indefinite can mean both not determined or infinite.
It can not make infinite of course, because at some point the Universe according to current standard model will cool out.But apart from that no problem, as long as the physical conditions exist to support it.
Look up RepRap. A 3d printer that can print itself, except for the electronics
Except for the electronics, motors, hot-end, heater, and so on (motors might be printed partly I guess).
They kind of already exist, see xenobots
Xenobots can also self-replicate. Xenobots can gather loose cells in their environment, forming them into new xenobots with the same capability.
Your link is missing the https:// so it doesn’t work in at least some clients. Working link.
Oops, thanks, corrected!
Cells suggest this is possible. Making it work right? That’s the hard part
Because you say mechanical that
doesmight preclude chemical reactions…At least a basic level of a real world self-replicating “device” in an abstract sense, you can “grow” some crystals given sufficient substrate liquid.
I think it is theoretically possible, and may be easier to realize at a microscopic scale since you can get a sufficient amount of liquid that can be considered a ‘functionally-infinite’ space and the device can more freely float around without having to worry about needing complex dextrous parts to put things in the right place.
A loose ball of dandelion seeds I put together would be my idea of a simple self-replicating ‘device’ that operates mechanically, in the natural world, at a human scale that I think meets your criteria. It floats around in the area and if there are dandelion fields where it goes, it can pick up the seeds, and if it bumps into a random obstacle in the landscape it will break into parts that can pick up other seeds. The only logical aspect of the device is how many seeds it is comprised of, and there is not a set sequence as to when it will break, because it just depends on where the wind pushes the ‘device’ into in the landscape.
Addendum: Condition 4 is hard to get around with my example, I can’t guarantee that when it breaks apart only dandelions that weren’t part of the original part would formulate the new part. Seems overly perscriptive if you count using its own constituent part to make a new part, then repairing itself up again as contravening that condition.
Isn’t this a Von Neumann machine, essentially?
Constraint 5 seems like an odd addition, why wouldn’t you want something like this to also be potentially useful? I would imagine if anyone does this for real it probably would break that constraint (as the xenobots do), because there’s a good chance the builders would try to accomplish something with it.
This is solely to keep the premise of the simple and clear. The device only has one objective: to create a copy of itself. The problem only concerns itself with whether it is theoretically even possible to construct such a device.
It’s been done with some researchers making a synthetic DNA analogue
