[HN Gopher] Mechanical computer relies on kirigami cubes, not el...
       ___________________________________________________________________
        
       Mechanical computer relies on kirigami cubes, not electronics
        
       Author : gnabgib
       Score  : 114 points
       Date   : 2024-07-04 16:03 UTC (6 hours ago)
        
 (HTM) web link (news.ncsu.edu)
 (TXT) w3m dump (news.ncsu.edu)
        
       | bondarchuk wrote:
       | Have they made even a single working logic gate? The video only
       | shows flipping bits back and forth by direct manipulation.
       | 
       | 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._ "
        
         | passwordoops wrote:
         | They do in the full paper (not open source & at this time no
         | one's put it on archive):
         | 
         | "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://www.science.org/doi/10.1126/sciadv.ado6476
        
           | bondarchuk wrote:
           | There's a link to the paper in tfa, it's open access.
        
         | abraae wrote:
         | I believe a NAND gate is required as the base on which all
         | other possible circuits can be built, so they need just to add
         | an inverter for potential turing completeness.
        
           | thih9 wrote:
           | Could be either {NAND}, or {NOR}.
           | 
           | https://en.m.wikipedia.org/wiki/Functional_completeness
           | 
           | https://proofwiki.org/wiki/Functionally_Complete_Singleton_S.
           | ..
        
           | mtizim wrote:
           | It's not, we just use NAND everywhere because they're easier
           | to make with transistors. You can get functional completeness
           | with a NOR instead, or alternatively with some different
           | combinations of other logical operators.
           | 
           | 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.
        
       | ItCouldBeWorse wrote:
       | Has anyone ever done a society re-bootstrapping from "mechanical
       | computation" back to working chips? As in-a planetwide em-event
       | knocks out all computation- how do we get factories like TSMC
       | back on track? How do we keep food production going? Could we
       | recover from zero, using only this set of mechanical computers
       | and basic instructions
        
         | bondarchuk wrote:
         | > _Has anyone ever done a society re-bootstrapping from
         | "mechanical computation" back to working chips?_
         | 
         | 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.
        
           | Teever wrote:
           | Don't forget about analog computers like mechanical
           | integrators or the anthykra mechanism.
           | 
           | Any device that would allow you to automate the production of
           | devices like gears and cam shafts would greatly increase the
           | bootstrapping rate.
        
             | bondarchuk wrote:
             | A mold is such a device. Doesn't have to be a mechanical
             | computer per se.
        
           | hypercube33 wrote:
           | Reading this thread I feel like I'm alive in the Star Trek
           | universe. yesterday an article about warp drive, now
           | discussing rebooting society after a global event and optical
           | computers... interesting
        
         | candiddevmike wrote:
         | > As in-a planetwide em-event knocks out all computation
         | 
         | 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.
        
           | TeMPOraL wrote:
           | > _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.
        
           | RodgerTheGreat wrote:
           | A scenario where general-purpose "unlocked" computers become
           | extremely rare and nearly every computing device is a non-
           | user-programmable appliance designed not to function without
           | remote servers and regularly cycled cryptographic keys seems
           | possible, though not inevitable. It would be a very stupid
           | kind of apocalypse to live through if a solar storm didn't
           | destroy many actual computers but did enough damage to brick
           | 99.999% of the computers that survived intact, and left
           | civilization with a crippling bootstrapping problem of
           | capital's own design.
        
             | candiddevmike wrote:
             | > left civilization with a crippling bootstrapping problem
             | of capital's own design
             | 
             | Sounds like the delicious irony humanity is known for.
        
           | rustcleaner wrote:
           | >if all you can find is an iPhone or some other trusted
           | compute platform you're probably SOL
           | 
           | 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.
        
         | abound wrote:
         | CollapseOS [1] comes to mind, but that's more about
         | bootstrapping simple chips for directing power as opposed to
         | rebooting society, but one could argue that the two go hand in
         | hand.
         | 
         | [1] http://collapseos.org/
        
           | lawlessone wrote:
           | Interesting. I had been thinking for a while of how i could
           | fine tune an LLM for this sort of thing.
           | 
           | 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.
        
             | burnished wrote:
             | The real deal breaker is probably the part where it would
             | confabulate details in processes where the details are
             | important. I'm just imagining trying to learn farming
             | techniques from an oracle that might instruct me to make
             | fertilizer that sounded sensible but caused nitrogen burn.
        
         | complaintdept wrote:
         | I'm not convinced society would be able to recover after a
         | collapse. We've extracted the easy to get resources already and
         | what's left is extracted and refined with some really advanced
         | technology. We can recycle a bunch of stuff, but that will only
         | get you so far. On top of that, most of our knowledge is stored
         | digitally, much of it in proprietary formats. If we don't
         | somehow manage to recover it before the existing expertise dies
         | out (assuming enough of it survives the initial catastrophe) we
         | may not get it back for a very long time, if ever.
        
           | wongarsu wrote:
           | We would be at a huge disadvantage on the energy front. Most
           | easily accessible fossil fuels are gone. Some countries have
           | oil deposits that can be reasonably extracted now that the
           | holes are made, but those places are few and far between.
           | 
           | 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.
        
             | thechao wrote:
             | Wind. Wind, by itself, without storage, isn't great for our
             | version of civilization. However, it'd totally be workable
             | for 19th c, at least, if not early 20th c. If there were
             | clever storage solutions, you could run our civilization,
             | but at a lower per capita energy budget, to begin with.
        
           | ianburrell wrote:
           | Most of the important resources we have extracted are sitting
           | around on the surface. When the steel rusts, it turns into
           | some of the best iron ore. Most of the stuff we threw away
           | ends up in landfills, mining those will get lots of resources
           | and knowledge. That would be plenty for pre-industrial
           | civilization.
           | 
           | 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.
        
             | roughly wrote:
             | > Most of the stuff we threw away ends up in landfills,
             | mining those will get lots of resources and 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.
        
           | dahart wrote:
           | > I'm not convinced society would be able to recover after a
           | collapse.
           | 
           | 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.
        
             | fragmede wrote:
             | Ever. Depends on the collapse, but one view is we'd never
             | get back. The easy sources of energy, ie coal and oil, have
             | all been mined/drilled already, and you need those to
             | jumpstart/bootstrap civilization to the point where you're
             | able to produce enough food in order to have excess
             | capacity of workers so you're able to get to renewable
             | energy. Without those easy sources of energy, you don't get
             | to have a post-collapse industrial revolution and you're
             | stuck repurposing what's left over from the before times,
             | and hoping it doesn't break because you can never make a
             | fab to produce ICs to replace computers that break.
             | 
             | 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.
        
         | MrsPeaches wrote:
         | Biggest issue is surely speed?
         | 
         | 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.
        
           | richk449 wrote:
           | If you have no computers, getting to kHz is a huge advantage.
           | Eniac ran at 100kHz (I think) and it was revolutionary.
        
           | omoikane wrote:
           | Note that mechanical computers aren't the only alternative to
           | electric computers, biological computing is another area of
           | active research:
           | 
           | 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:
           | 
           | https://xkcd.com/2173/
        
             | throwAGIway wrote:
             | You can't get biological computers without having very high
             | speed computers though. This field of biology is very
             | reliant on computer analysis.
        
         | milkshakes wrote:
         | not mechanical computers but
         | 
         | http://collapseos.org/
        
         | retrac wrote:
         | Babbage went down the wrong rabbit hole. The technology of the
         | 1860s was sufficient to make an automatic programmable
         | computer. If you can make (or salvage) wire, and make simple
         | sheet metal parts (brass will do) then you can make
         | electromagnets, which means you can make relays. And there you
         | go. No multimedia streaming, but automatic control and
         | communication at a distance, yes.
        
           | nine_k wrote:
           | You would need plenty of electricity though.
           | 
           | 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))
        
             | roughly wrote:
             | I'm actually curious about the linguistics of something
             | like a telegraph for ancient Egypt - I'm not particularly
             | familiar with the Egyptian writing system from that era,
             | but a strongly pictographic language, and one in which they
             | seemed to regularly intersperse actual pictures and do
             | things like manipulate symbol size to convey information
             | doesn't seem to immediately suggest translation to an
             | encoding like Morse like phonetic written languages do.
             | 
             | 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)
        
               | andrehacker wrote:
               | - Make a list of the most common (spoken) words - Sort
               | them by usage frequency (most used words on top) -
               | Associate a unique sequence of 0 and 1 (dot and dash) -
               | Use shorter sequences for common words, longer ones for
               | the words below - As you don't transit letters but words
               | the transfer rate is much higher than in "modern"
               | telegraph systems - profit ?
        
               | dekhn wrote:
               | So basically a prefix-free code with a symbol table of
               | words.
        
               | retrac wrote:
               | Getting off topic here but, the Ancient Egyptian writing
               | system was only marginally pictographic. The fully-
               | developed system is essentially phonetic, using about ~40
               | symbols to represent sounds, and a couple hundred
               | pictograms (often interchanged with the full spelling).
               | Closest analogy is probably the Japanese writing system,
               | but with many fewer kanji. Carved hieroglyphs were highly
               | formalized and ceremonial in nature, but ultimately, the
               | quail chick means "u" and a foot means "b". (We inherit
               | the letter "b" from the shape of that foot hieroglyph.)
               | 
               | Have a look at the handwritten form, as would be used for
               | papyrus books or official letters: https://upload.wikimed
               | ia.org/wikipedia/commons/9/91/A_page_f...
        
               | roughly wrote:
               | Interesting, I didn't know that!
        
               | jf wrote:
               | I highly recommend that you read the book "Hieroglyphs: A
               | Very Short Introduction" which I expect you will enjoy as
               | much as I did: https://academic.oup.com/book/470
               | 
               | 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"
        
               | roughly wrote:
               | The Very Short Introduction series is fantastic - they
               | really do a great job of distilling the core of a subject
               | to give a lay person the conceptual framework to
               | appreciate the topic. I've enjoyed every one I've read.
               | 
               | > 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"!
        
               | contingencies wrote:
               | _The Information Super-Nile_. I like it. Perhaps elements
               | of language used in cognitive expressions would begin to
               | mirror through metaphor geographical terms used for
               | proximity of major Nile features to the capital. Messages
               | would become rafts. System operational periods, seasons.
               | Fog of war would become a stagnant pond, or stilled flow.
               | Riparian plants, ever-present information service
               | providers such as scribes and couriers. Riparian birds
               | with fleeting habits, commercial traders waiting to
               | pounce in to action based on on news from afar.
        
           | klyrs wrote:
           | And here I've always thought that Babbage's big mistake was
           | using decimal instead of binary.
        
           | lcouturi wrote:
           | But Babbage started in the 1830s, not the 1860s.
        
         | brookst wrote:
         | Not exactly that, but Souls in the Great Machine explores a
         | society that relies entirely on mechanical computers. Good
         | book.
        
         | bee_rider wrote:
         | What do you mean, done a society? Like a simulation or a
         | thought experiment (plenty, I'm sure, with "varying" levels of
         | rigor). Actually run the experiment? I'm sure not.
         | 
         | 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.
        
         | duped wrote:
         | The big problem is that modern chip manufacturing is impossible
         | without the petrochemical industry, which itself needs the
         | petrochemical industry to operate.
         | 
         | 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.
        
         | dudinax wrote:
         | https://en.wikipedia.org/wiki/The_Difference_Engine
        
         | dekhn wrote:
         | Only in science fiction, I think. See
         | https://www.amazon.com/Souls-Great-Machine-Greatwinter-Trilo...
         | in which case natural neural-based computers are used to
         | implement digital computation.
         | 
         | I imagine the folks who built this:
         | https://en.wikipedia.org/wiki/Turing_Tumble may have used
         | computers to design/optimize the parts.
        
       | passwordoops wrote:
       | Link to the paper (sorry it's not open source!):
       | 
       | https://www.science.org/doi/10.1126/sciadv.ado6476
        
       | colordrops wrote:
       | What are use cases of this? High radiation or otherwise extreme
       | environments?
        
         | snailmailman wrote:
         | On Venus, the air corrodes any electronics incredibly quickly.
         | Making it a difficult environment for spacecraft.
         | 
         | With a mechanical solution, the parts can hopefully be more
         | durable, as electrical conductivity could stop being a
         | requirement.
        
         | novaRom wrote:
         | I think similar approaches might be useful in micro-
         | electromechanical systems (https://en.wikipedia.org/wiki/MEMS)
        
       | hughlett wrote:
       | Go Pack!
        
       | brotchie wrote:
       | Neal Stephenson's The Diamond Age IRL
        
       | grondilu wrote:
       | > Mechanical computers are computers that operate using
       | mechanical components rather than electronic ones.
       | 
       | 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.
        
         | jes5199 wrote:
         | sure, but how many electrons do we typically move around as a
         | single signal
        
           | dekhn wrote:
           | Few, if any; instead, it's typically the propagation of an
           | electromagnetic wave that transmits a signal:
           | https://en.wikipedia.org/wiki/Speed_of_electricity
        
             | pyinstallwoes wrote:
             | what is the electromagnetic wave made of, what's the
             | substrate it is composed of and moving through?
        
               | dekhn wrote:
               | The wave is electromagnetic energy passing through a
               | waveguide (typically copper) mediated by electrons. See
               | https://en.wikipedia.org/wiki/Waveguide
        
             | reaperman wrote:
             | "Few", yes. But definitely some. I don't think you can have
             | propagation of EM wave through a conduit without at least
             | pushing one electron into the conduit and removing one
             | electron from the other side of the conduit.
        
               | dekhn wrote:
               | Yes, but it's subtle; see
               | https://en.wikipedia.org/wiki/Drift_current and
               | https://en.wikipedia.org/wiki/Drift_velocity and
               | https://en.wikipedia.org/wiki/Electron_mobility for more
               | details
               | 
               | 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.
        
               | reaperman wrote:
               | Indeed - I thought most college Physics 2 courses teach
               | that electrons actually move quite slowly through
               | conductors. It's the "wave" which propagates near the
               | speed of light, not the particles.
        
               | dekhn wrote:
               | My mistake was being a biologist, and skipping or
               | sleeping my way through the EE part of physics :) and
               | then saying the wrong thing in front of some very smart
               | people
        
               | reaperman wrote:
               | Lord, I make that mistake on HN nearly every month. At
               | least you didn't have a "Putnam award" moment:
               | 
               | https://news.ycombinator.com/item?id=35079
        
         | gchamonlive wrote:
         | Maybe not more efficient, but maybe more resilient to
         | electromagnetic storms, not prone to overheating (maybe),
         | etc... Maybe it's about fitting constrained scenarios.
        
           | Loughla wrote:
           | It seems like they may be prone to overheating in some
           | fashion. All that electricity and motion has to cause some
           | kind of thermal load. Or am I way off base?
        
             | chongli wrote:
             | Yes. Friction is usually the limiting factor in mechanical
             | systems. It causes a lot of heat, noise, stress, and wear
             | on all interacting parts. It requires all sorts of messy
             | approaches to mitigate, such as lubricants and bearings.
             | Electricity is basically magic by comparison.
        
           | Terr_ wrote:
           | > but maybe more resilient to electromagnetic storms
           | 
           | If you mean solar flares, that's generally an issue with long
           | transmission lines, as opposed to very small circuits.
        
         | reaperman wrote:
         | Taking this to its logical extreme, photonic computing should
         | be significantly more efficient than electronic computing.
         | Eventually.
         | 
         | 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.
         | 
         | https://en.m.wikipedia.org/wiki/Landauer%27s_principle
        
           | infogulch wrote:
           | The big problem in photonic computing is actually making an
           | optical transistor, i.e. a switch where the presence of
           | photons coming from one source controls whether of photons
           | coming from another source pass. This is harder than
           | electrical transistors because photons are bosons and don't
           | interact with each other, so even theoretically this is hard
           | to imagine.
           | 
           | Papers that claim some progress pop up every once in a while
           | but I haven't seen anything promising yet.
        
             | reaperman wrote:
             | Yes, general photonic computing is mostly "theoretical" at
             | the moment. Still, discussion of theory is important. I
             | wish I could add more to your comment but I'm so far out of
             | my depth that it would be simply misleading (blind leading
             | the blind). I believe there's theory saying it's
             | theoretically possible to create efficient photon<->matter
             | interfaces which could achieve transistor-like behavior ...
             | but there's too much I don't understand to be able to
             | evaluate whether there are inherent limitations which kill
             | the practical application of the proposed theoretical
             | mechanisms.
             | 
             | I think we have seen 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.
        
       | theturtle32 wrote:
       | Kinda reminds me of QAM
        
       | tombert wrote:
       | If I ever become a billionaire, I am going to have an entire big
       | room in my house dedicated to pre-electric computers. It's
       | amazing how much stuff got borderline-trivial once the transistor
       | became ubiquitous, and stuff like The Writer Automaton has always
       | been something that has utterly fascinated me.
        
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