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Analog computation. I don't mean just vacuum tubes or even electronics at all. Mechanical analog computing is insane when you get down to it. You have special
by calamari4065 3y ago
Analog computation.
I don't mean just vacuum tubes or even electronics at all. Mechanical analog computing is insane when you get down to it. You have special shapes that move against each other and do calculus.
We make these mechanical models as analogs of more complex physical systems. We can turn huge calculations into relatively simple machines. That we can roll two weirdly shaped gears together and get an integral out says to me something very profound about the universe. I find it to be one of the most beautiful concepts in all of the sciences.
What's even more wild is that we can take those mechanical analogs of physical systems and build an electronic analog out of vacuum tubes. That vacuum tubes work at all is just completely insane, but it's some absolutely beautiful physics.
And yes, there are equally beautiful problems that can only be solved in the digital domain, but it just doesn't speak to me in the same way. The closest thing is the bitwise black magic like fast inverse square root from a special constant and some arithmetic. Besides, that's more a property of number systems than it is of digital computation.
I understand how and why digital took over, but I can't help but feel like we lost something profound in abandoning analog.
- 29athrowaway 3y agoLike Soviet water computers?
- Bjartr 3y agoLike naval mechanical targeting computers that use clever cam and gear arrangements. https://youtu.be/s1i-dnAH9Y4?si=oHHJGRqnFx-ydQu1 https://youtu.be/s1i-dnAH9Y4?si=oHHJGRqnFx-ydQu1
- calamari4065 3y agoHah, this is the exact video I was referring to in the sibling comment. This is what really captured my imagination with regard to mechanical computers
- calamari4065 3y agoLook around on YouTube. There's some fascinating videos from the 1950s on US Navy mechanical firing computers. These machines can calculate ballistic trajectories with incredible accuracy, accounting for the relative motion of the ships, wind speed, and even the curvature of the earth. Those calculations are not at all trivial!
- 29athrowaway 3y agoYes. They are like sliding rules on steroids.
- phillypham 3y agoIn ML/AI space, at least some people thing analog computing is the next big thing, https://www.forbes.com/sites/karlfreund/2021/09/23/ibm-research-says-analog-ai-will-be-100x-more-efficient-yes-100x/?sh=9b4e7f4129b3 https://www.forbes.com/sites/karlfreund/2021/09/23/ibm-resea.... It hasn't taken off, yet, though.
- calamari4065 3y agoI know, I've had my eye on this topic for a while. Honestly it seems like a perfect application. Neural networks are analog systems. An analog computer can represent neurons very accurately and the entire network is inherently parallel, for free! I can't wait to see what comes out of this research
- spacecadet 3y agoI agree.
- rusticpenn 3y agoMy research was in this direction. We already know that these analog neural chips could be orders of magnitude faster than digital equivalents. There is also a lot of military research going on in this area for few decades. However architecture innovations are much faster on software level and dedicated hardware approaches have not been able to catch up. Once things slow down on software level, slowly hardware llms could become the norm.
- calamari4065 3y agoI don't venture too far into analog electronics so I don't know for sure, but it seems like an analog FPGA type system could really take off.
- rusticpenn 3y agoCypress has been doing something like that for a long time now. Reconfigurable Analog electronics is an interesting field.
- jvm___ 3y agoAnalog tide-predicting machines are fascinating. The tide height is a function of the earth/sun/moon systems. Earth and Moon aren't at a fixed distance from eachother, and neither is the sun, so every day is a unique tide but you can predict the range. The analog way to do it is to make a gear for each point of data in the system and synchronize all their gears. Then you use them all to rotate one final gear, which will show you the prediction for the time you've chosen.
- calamari4065 3y agoI think this is a great example. It's pretty easy to mentally connect the orbit of a planet with the ratio of gears. Once you really understand how these systems are an analog of a physical problem, everything makes so much more sense
- jodrellblank 3y agoI used to know nothing about Lord Kelvin except he said things like "It seems, therefore, on the whole most probable that the sun has not illuminated the earth for 100,000,000 years, and almost certain that he has not done so for 500,000,000 years"[1] and allegedly "everything which can be discovered, has been discovered"; until last year's Veritasium video on YouTube[2] about analog computers, and learned he invented tide-predicting analog computers to "substitute brass for brains" and add sinusoidal curves, and a mechanical integrator to separate out individual sinusoidal frequencies from the sum. [1] https://zapatopi.net/kelvin/papers/on_the_age_of_the_suns_heat.html https://zapatopi.net/kelvin/papers/on_the_age_of_the_suns_he... [2] https://www.youtube.com/watch?v=IgF3OX8nT0w https://www.youtube.com/watch?v=IgF3OX8nT0w from about 3 minutes.
- kolinko 3y agoYes! Also, most people don’t know that the word „Analog”, as in „analog circuits” comes from „analogy”.
- calamari4065 3y agoI didn't make that connection until my late 20s and when I finally did, it radically changed how I look at and understand analog systems. In today's world, we still build analogs, we just coerce them into strictly numerical, digital models. I don't know if you can call it better or worse, but digital is definitely less magical and wondrous than mechanical analog systems.
- gcanyon 3y agoVeritasium did a very nice video about the analog tide computers: https://www.youtube.com/watch?v=IgF3OX8nT0w https://www.youtube.com/watch?v=IgF3OX8nT0w
- Spooky23 3y agoI agree. I remember climbing into the turret of the USS Massachusetts and playing with the ranging computer. It was just impressive that a geared device could do pretty complicated math in real time.
- debian3 3y agoYou can have a look at that pinball machine. You will be amazed. https://youtu.be/ue-1JoJQaEg https://youtu.be/ue-1JoJQaEg
- 8bitsrule 3y agoNature, almost completely analog, has been around a thousand times longer than humans. How many times has 'evolution' used digital methods to accomplish something? Perhaps we've chosen to switch to digital because we're in a hurry and its easier ... in hopes of, some day, asymptotically approaching the advantages of analog.
- calamari4065 3y agoThe main reason is that digital computers are so incredibly, overwhelmingly more flexible than analog. Analog computers are (generally) bespoke single-purpose devices. It really isn't too far off to imagine analog computers as code made physical, with all that entails. Imagine writing a program if every time you wanted to change something you had to cut a new gear, or design a new mechanism, or build a new circuit. Imagine the sheer complexity of debugging a system if instead of inspecting memory, you have to disassemble the machine and inspect the exact rotation of hundreds of gears. Analog computing truthfully doesn't have enough advantages to outweigh the advantage of digital: you have one truly universal machine that can perform any conceivable computation with nothing but pure information as input. Your application is a bunch of binary information instead of a delicate machine weighing tens to hundreds of pounds. Analog computing is just too impractical for too little benefit. The extra precision and speed is almost never enough to be worth the exorbitant cost and complexity.
- stormfather 3y agoYeah but ChatGPT is using $700k per day in compute (or was in April). Someone's going to make an analog machine that uses mirrors and light interference or something to do self attention and become very, very wealthy.
- calamari4065 3y agoYes, this is an active area of research. Neural networks are a very good application for analog computing (imo). You have a ton of floating point operations that all need to happen more or less simultaneously. And what are floating point numbers if not digital approximations of analog values? :) This can be implemented as a network of transistors on a chip, but driven in the linear region instead of trying to switch them on as hard as possible as fast as possible. Which is, I believe, what researchers are trying to do. There are also some interesting ideas about photonic computing, but I'm not sure if that's going anywhere. A few months back, someone on YouTube attempted to design a mechanical neural network as a single 3D printed mechanism. It ended up not working, but the concept was pretty solid.
- fulafel 3y agoElectronic analog computing is also still being researched, eg https://arxiv.org/abs/2006.13177 https://arxiv.org/abs/2006.13177 ("Analog multiplication is carried out in the synapse circuits, while the results are accumulated on the neurons' membrane capacitors. Designed as an analog, in-memory computing device, it promises high energy efficiency")
- pyinstallwoes 3y agoWhat are some... surprising and relatively easy ways to feel the magic of analog computation?
- calamari4065 3y agoSlide rules, for a start. This Wikipedia page contains a lot of magic as well: https://en.m.wikipedia.org/wiki/Differential_analyser https://en.m.wikipedia.org/wiki/Differential_analyser As for something you can easily get your hands on, micrometers are incredible. A simple screw and graduated markings on the shaft and nut give you incredibly precise measurements. You can also find mechanical calculators (adding machines) on eBay. But those really aren't very sexy examples of the concepts. Analog computers aren't very common anymore. Your best bet is visiting one of the computer museums that house antique machines. Or watching YouTube videos of people showing them off. There's plenty of mechanical flight computers in particular on YouTube. If you have access to a 3D printer, there's plenty of mechanisms one can print. The antikythera mechanism is a very interesting celestial computer from ancient times, and 3D models exist online.
- pyinstallwoes 3y agoI like synthesizers and modular synths. So maybe I play with music analog computers. No idea how to make them do useful computation though!