Mechanical computer relies on kirigami cubes, not electronics
news.ncsu.edu
news.ncsu.edu
Edit: I am happy to report yes:
"Last, we explore the metastructure as simple mechanical logic gates. Figure 8 (C and D) demonstrates the achievement of both “OR” and “AND” logic gate operations by using independent bistability in local elements."
"Mechanical logic gates Last, we explore the metastructure as simple mechanical logic gates. Figure 8 (C and D) demonstrates the achievement of both “OR” and “AND” logic gate operations by using independent bistability in local elements. To facilitate the reading of output information (see more details in fig. S17A and the Supplementary Materials), we use a supported height-adjustable flat plate on the top to cover a small region of the platform. Its initial state is set as an output of “0.” When the plate is even and elevated, it outputs "1," otherwise "0" for the cases of either being tilted or lowered. The configurations of the top plate are determined by the pop-up ("1") or pop-down ("0") motions of three supports bonded to the bistable elements as inputs. A pyramid support denoted as P1 is placed in the center with two other neighboring supports surrounded, e.g., cuboids of S1 and S2 and pyramids of P2 and P3 for the OR and AND logic gate, respectively. Figure 8C and fig. S17B show that when P1 is popped up and fixed, popping-up either S1 or S2 or combined as inputs leads to a stable and evenly elevated plate on the top as an output of "1" for an OR operation, because one point contact at P1 alongside one plane contact at S1 or S2 will render a stable and even surface. For the case of AND logic gate shown in Fig. 8D and fig. S17C, three pyramid that supports Pi are free to pop up or down, providing the point contacts to support the top plate. Only when the plate is supported by three pop-up point contacts, i.e., P1 = P2 = P3 = 1, it will generate a stable and evenly elevated plate as an output of "1" for an AND operation. We note that most previous mechanical logic metastructures are limited to 1D and 2D structural forms (1–3, 11, 19, 20, 26, 29, 41). Our design extends the structural form of the mechanical binary logic computation to a 3D structural form. In Fig. 8 (D and E), we demonstrate the logic operation in only one zone. In particular, given the independent bistability of each local elements, such design principles can be readily applied to multiple zones for conducting a myriad of parallel mechanical binary operations on the same metastructure platform (see details in fig. S18). Moreover, by altering the structural components as schematically illustrated in fig. S19, we can also conduct “NOR” and “NAND” binary logic computations in our designed platform.
https://en.m.wikipedia.org/wiki/Functional_completeness
https://proofwiki.org/wiki/Functionally_Complete_Singleton_S...
https://en.m.wikipedia.org/wiki/Functional_completeness
We even implement AND gates with NANDs in electronics (because they're way simpler), but we might not have to limit ourselves to a single base gate with mechanical computers.
That makes it sound like you could also do a NOT with XNOR, which is only the case if you can use a constant 0. But that would similarly also be the case for a XOR, but with the requirement of a 1.
Is this trying to straddle the line between analog and digital computing? Because it sounds like they are describing a crippled analog computer system.
There's plenty of non-binary schemes used in modern digital systems though. Modern NAND flash is one instance, for example QLC SSD drives store 16 distinct levels per storage cell (allowing each to encode the equivalent of 4-bits of data). Another example is 64-QAM, a modulation scheme used in a variety of places, including 802.11n Wi-Fi and Digital Terrestrial television (among others), which forms symbols out of two out of phase sinusoids, each of which can take up to 8 amplitude levels.
And even electronic computers haven't always been binary, one of the early Soviet computers was ternary, relying on 3 digits rather than the more familiar 2, to do all of its core computing functions.
For anyone who's excited about mechanical computers, perhaps it is worth reminding that an electron is about a thousand times lighter than a nucleon. Therefore, it's probably fair to say that mechanical computers will always be more energy consuming than electronic ones, because they fundamentally need to move atoms around to operate.
I was pretty surprised about this since I had mistakenly believed that electrons had a velocity near the speed of light, which I think is only true in particle accelerators.
In short, nearly everything I have learned is from saying dumb things in front of very smart people who instantly understood my misunderstanding and knew exactly how to explain it so I understood. That includes Sanjay Ghemawat and Jeff Dean telling me "your idea isn't so good, it's n-squared, here's a linear solution"
AlphaPhoenix did an amazing experiment to measure the speed of electricity FWIW. His other videos are incredible as well and explain EM physics in an absolutely outstanding way.
https://www.reddit.com/r/engineering/comments/qxrsrp/the_big...
What if you made a really big circuit consisting of a battery, switch, lightbulb, and a wire that goes out 300k km on either side making a circuit that should take 1s at the speed of light to travel through. How long after closing the switch will it take for the light to go on?
If you mean solar flares, that's generally an issue with long transmission lines, as opposed to very small circuits.
Is that the end-game? Is there anything that would theoretically get closer to the Landauer limit than photonic computing? It’s way out of my element but I suppose this is a good venue to ask the question.
Papers that claim some progress pop up every once in a while but I haven't seen anything promising yet.
I think companies have come up with some practical applications of limited photonic “computing” at interface edges but I’ve heard that until we no longer need to convert photonics to electronics it won’t surpass electronics for general computing.
Possibly a strech, but transistors are basically current amplifiers, so their optical equivalent should be... lasers. Indeed lasers are optical amplifiers. Whether or not they can be turned into logic gates as transistors can, I don't know.
Then again, Chuck Moore's GA144 shows there's still plenty of room when it comes to optimizing electron-based computing for those kind of extreme scenarios as well.
With a mechanical solution, the parts can hopefully be more durable, as electrical conductivity could stop being a requirement.
Thankfully not, since it hasn't been necessary yet... At any rate I would guess mental arithmetic would be much more practical than mechanical computers, and then we could probably skip straight to vacuum tubes and punch cards.
Any device that would allow you to automate the production of devices like gears and cam shafts would greatly increase the bootstrapping rate.
This is an impossible scenario. There will always be working computers somewhere, either shielded, excluded from the disaster, or by luck. Now they may not be the easiest thing to get to, and if all you can find is an iPhone or some other trusted compute platform you're probably SOL.
Good point. The computer age is already poised to become a historical dark age; increasing adoption of trusted computing is only going to make this more severe.
On the other hand, some of it is necessary; on the other, security is the sworn enemy of sugar, spice and everything nice.
Sounds like the delicious irony humanity is known for.
This reason alone should be impetus, for national security reasons, to severely tax products containing universal machines the device owner does not have full control over (by additional purposeful actions beyond owners' simple ignorance of the technology). I say a 100% sales tax on the retail price is fair, all tax proceeds going to fund GNU-compatible competition to the likes of iPhone and Playstation (and your proprietary microwave, and car, and TV, and ...). A post collapse society having to deal with iPhones hopefully will adopt the [corporate] death penalty for proprietary shenanigans like this.
It is borderline treasonous how many people will die because your product's bootloader was locked! Unforeseen consequences, Gordon.
It would act as oracle of sorts for how to start farming, build machines, etc.
The power and hardware requirements would kind of make it useless though.
On the other hand there would be vast resources of refined steel, aluminum and other metals. The average home contains materials that would make a monarch from 200 years ago jealous. Not to mention invaluable machinery like precision lathes. You just need to find a way to power them.
Without a readily available source for fertilizer and the supply chains necessary for modern agriculture we couldn't possibly feed more than a billion people or so. But whatever society rises from the ashes of that catastrophe could use the abundant building materials to harness water and wind energy and climb back up the technological ladder.
Computing would be pretty low priority though, first we would need to get farming back on track. Without modern farming you need most of the population to work in agriculture, preventing you from making any significant progress in other fields.
The big problem is used the easy energy for industrial civilization. Solar mirrors and wind would be possible, but low density until more advanced. We assume that our energy-heavy industrial civilization is the only way, but it is possible that low-energy or low penetration industrial is possible. There is also possibility of biologically developed civilization.
Lots of current knowledge would be lost but there are tons of books from current and earlier eras. If those are preserved, there would be plenty of knowledge for early industrial civilization. In fact, the main problem would be finding anything or getting caught looking at past. One thing we could do today is make more durable books, and then reprint the important things like practical knowledge.
I actually think this is something that’s inevitable for us today. The amount of high-value material that we’ve “discarded” by collecting it into one place and then ignoring it - the processes need to be developed, but at some point we’re going to recognize how much useable stuff we’ve just been piling up in the corner.
Like ever? Or do you have a time frame in mind? Our current state is evidence enough that people can get there eventually. This is all fun imaginary speculation, of course, but I’d wager that even if we lost all written/stored information and the scientists and engineers, just knowing what was possible puts the remaining people way ahead of where we were in the past. We didn’t know what was possible the first time through, didn’t know what to look for. Having memory of what existed and even a child’s understanding of how it worked, passed by word of mouth, would probably be enough to dramatically accelerate progress compared to it’s natural development.
Generations after the collapse, the stories of what's possible will be viewed the same way we view stories of dragons from the middle ages. Fiction.
I don’t necessarily buy the energy argument. Why would it have to be coal & oil primarily? Maybe it doesn’t. Coal and oil aren’t gone, but there’s also ample solar, wind and hydro to power a new society. Would losing computers actually cease coal & oil production completely? I kinda doubt that. I’m sure it would be a temporary setback and slow things down, but there was a lot of coal and oil production before computers.
The hypothetical question here seemed to already assume that food production and energy aren’t gone, it was just whether we can rebuild electrical compute without computers, based on knowledge of mechanical compute.
We can certainly imagine some epic worst-case scenario where no people with knowledge of any engineering survives, no books survive, and future humans have to start from absolute scratch. That seems far less likely than the probability that some of our knowledge carries. But even in the total doomsday scenario, what we have already is evidence that it worked the first time, and yes we can imagine hypotheticals that make it harder, but we already survived stories of dragons once, right? The default assumption kinda has to be that it might happen again given time.
Sure we do. Humans today could easily build a new pyramid if we chose to. You might be conflating the question of proving exactly what they did with the question of whether we could achieve a similar result today, those are two very different things and we’re discussing the latter. There is written evidence about the construction of the pyramids in Egypt from 4500 years ago, and anthropologists have have multiple plausible techniques with evidence (in part because we know there were multiple different construction techniques employed). If the knowledge was lost at some point, it’s not anymore.
Cortés and the conquistadors could have done it too, without knowing exactly how it was done before. Just having seen them, he’d know it could be done, and if he cared he could have figured it out. The Spaniards didn’t want to Mayan build pyramids, they were busy building castles and monuments - their own version of pyramids.
Computers are measured in MHz and GHz. How do you even get close to that using mechanical means?
Speed is also a core value proposition (to use contemporary parlance) of computers I.e computers can carry out calculations at a rate of MHz/Ghz. If you want to talk in any meaningful sense of “computation”, and the usefulness thereof, speed of computation is a key metric.
I reckon cooling would be an even bigger concern than it is currently.
https://en.wikipedia.org/wiki/Biological_computing
Speed and cooling might be less of an issue considering the scale which biological processes operate.
Although biological computing sounds a lot like just doing everything by hand:
- I don't know anything about fluid mechanics
- The 'exhaust' is water, so I could only really operate this thing in the bath
BTW one of my favorite crazy ideas is that by the times of the Middle Kingdom, ancient Egypt had all the material resources needed to build a phone system, or at least a telegraph system, very useful in a large country. Zinc and silver to create batteries. Plentiful copper, gold, and silver to create any kinds of wires, and techniques to finely process it. Some amounts of magnetic ferrous alloys from meteorites, and likely access to iron ores to produce more. Only very small amounts are needed for kernels of electromagnets and membranes. Paper and resin-based glues could be used to produce wire insulation. Very certainly they were able to work any available materials with good precision and sophistication.
What they lacked was a good theory required to connect the pieces into a working phone system, like that of late 19th century.
I sometimes think about what we are currently oblivious of, because certainly we have a plethora of resources to work with. (See also: https://en.wikipedia.org/wiki/His_Master%27s_Voice_(novel))
In other words, if the ancient Egyptians had found themselves with the technology to create something like a telegraph, I wonder what they would have done with it - what possibilities suggest themselves given the visual representation of the Egyptian language.
(I could actually see something like the Incan quipu being a much easier translation, if we’re talking premodern “written” languages)
Have a look at the handwritten form, as would be used for papyrus books or official letters: https://upload.wikimedia.org/wikipedia/commons/9/91/A_page_f...
In short: Hieroglyphics were phonetic, but they eluded translation for centuries because only a small number of people could read and write them, and (importantly) the directions that the pictographs faced determined the direction that you’d read in.
My favorite fact from this book is that the hieroglyphic word for “cat” is the combination of the sounds for “me” and “ew”
> My favorite fact from this book is that the hieroglyphic word for “cat” is the combination of the sounds for “me” and “ew”
Chinese is similar - the word for “cat” is “mao”!
Anyway it is generally impossible I’m pretty sure to do a “let’s build a society” experiment. Even if you try really hard, it always favors strategies that have a positive expected value but an unacceptably high chance of failure, right? Like you know the worst case if you actually fail is that you return to the real world and go to the hospital, so it is fine to take a risk that would give you like a 5% chance of getting an infection and dying. This has a 95% chance of working out but you’ll get a critical failure if you roll the dice over many generations.
The modern industrialized economy is built on industrial chemical production which stems from oil. If we lose the ability to extract or distribute oil it's going to be hard to bootstrap society.
But if that happens we're all going to die from common infections and starvation before we worry about getting YouTube back online.
I imagine the folks who built this: https://en.wikipedia.org/wiki/Turing_Tumble may have used computers to design/optimize the parts.
https://codehiddenlanguage.com/
I love this book because it does so in such a playful and imaginative way that you might not realize you are learning exactly how a computer works. But you are..
Assuming a planetwide em event is a pretty major wrench in the works and definitely puts you back a lot further in terms of how to rebuild the technology ecosystem.
I rather like the idea of rotating retroreflectors read by laser from orbit to send data back.
It’s very neat to see an NC State article on here