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Comment by CommieBobDole | Hacker News Reader

I think the only real answer to this is "never". 20 people is well below the minimum viable number required to create a large population, and since the first step in building a CPU is "create a large industrial civilization", it can't ever happen.

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I agree. If you have ever read the book Crystal Fire, about the work done at Fairchild Semiconductor in the 1950-70s, it took the best and brightest decades to solve the chemistry and engineering challenges present in building transistors and ICs. Even with 20 skilled PHDs as a starting point, I don't think you could overcome the practical manufacturing challenges in any reasonable amount of time.

one of the caveats of the question though is the people who are put there already know exactly what they need to build and how to build it; so you don't need 20 phd's to re-solve the chemistry and engineering challenges. It's almost purely a (still not solvable with 20 people) manufacturing problem.

These are 20 people who live infinitely long, never age, and can work 12 hour productive days.

As long as there is no single step that requires more than 20 simultaneous workers, I don't see why it's not solvable with these 20 people.

This also assumes that as each step is solved, it doesn't require a continued human presence. I.e. if you develop electricity, the electrical plant needs to be automated and run itself without human (or computer) interaction. The laws of entropy are going to come into play eventually. You might not be able to keep everything working for long enough to make meaningful progress.

And as long as this single step does not take more than 12 hours.

It will just take a long time, though…

Naturally, but the original question was how long.

They may know exactly how to build something and what they need, but as I understand it they would not get full documentation about the island itself. What resources are where and what the composition of ore exactly is. So they have to develop an understanding of resources they have and that requires a laboratory and sensitive equipment.

Either way I think that lots of machinery has to be supervised 24/7 and they can work only 12h a day per rules so they would probably be left with only 10 simultaneously active workers. With 10 workers I would say it's just impossible.

Are you disregarding the hypothetical assumptions of the question? Particularly that the people would not tire, age, or die, and already have all required knowledge.

Or, is your argument that the tasks involved in building an 8086-level computer and prerequisites are not serializable?

Fair enough, I didn't properly read the conditions. Assuming (as the question does) that they're immortal and all-knowing, have access to all needed resources in raw form, and can entirely devote their lives to the project, I would change my answer to "an extremely large but non-infinite amount of time".

I think the top answer radically understates the difficulty of the problem; not only would they need to build all of those things, they would need to build the tooling to build the components needed to build all of those things. And for those components, they would need to build the tooling to build the components used to build the components, and so on.

Honestly, I think that even semi-accurately estimating the complexity of the work to be done would be months of work. To actually do it with 20 people, hundreds of thousands or maybe millions of years?

There are interesting places that technological development could have “skipped ahead” that we can only see in retrospect. For example: it was possible to invent photolithography as soon as we had lenses, which means—provided we had the knowledge—we could have started with integrated circuits, skipping the relay, vacuum-tube, and discrete-transistor phases of computer development.

Similar things are likely true in other steps given that we would have access to a huge breadth of “recipes” for rather-more-optimal chemicals (e.g. doping agents, etchants, electrolytes, etc.) than we started off trying. The reagents of these chemicals frequently don’t take any more effort to dig out of the ground than the ones for the less-efficient products; and they don’t take more sensitive or well-sealed equipment to react together, either. They just took sensitive, well-sealed equipment to discover, or were only accidentally discovered as byproducts or other processes we ended up only starting later on (like petroleum distillation.)

Could perhaps have jumped to integrated circuits as soon as transistors could be built, but vacuum tubes were buildable well before transistors. I think that with the existing industrial base as one resource, and knowledge of future technology as the other, semiconductor grade silicon could have been produced as early as the mid 1930s. Not much sooner. Germanium is rarer and less optimal in many ways (small band gap) but it is easier to purify. Could you make simple ICs based on germanium instead of silicon earlier than the mid 1930s? I don’t know what additional complications the germanium path might have. Maybe it’s impractical for reasons other than material purity.

And to answer your other question, there might still be a barrier that we're not considering. Something along the lines of "one of the manufacturing steps requires a perishable chemical, and because of other dependencies there's no way that 20 people can coordinate the steps to produce the minimum required quantity of the chemical and do the other steps so that all of the needed components are available at the right time before they go bad." So there's a unknown-likelihood chance that it's still impossible.

That's basically what the top answer says, but it's still an interesting question. Especially since it shows people how interrelated different aspects of the economy are to each other.

A maximum extend to which you can get with "sticks and stones" is about level of seventies in IC technology, which effectively mean it is useless for the purpose.

At that point, the "you have to build manufacturing machinery to build more manufacturing machinery" gets close to being exponential, and you will spend double the time just to get past the critical mass of IC controlled machinery to do something that looks like a nineties era fab complex.

First ASML steppers required close to no complex parts: nearly fully analog/mechanical they were. The last gen ones however require megatons of electronics, and manufacturing facilities the size of football stadium for nearly every complex part.

You realize PDP-8/i was made in sixties? and would be happy to run Intel 8088 microcode if programmed correctly?

Yes, and its computational power does not get you much past what was already possible for engineering computing.

You need nineties level for doing useful things that matter: monte carlos, FEM, CFD, molecular kinetics, nuclear physics etc

"Windows 1.0"

I'd disagree -- but I think an important question is whether the goal is to create an industrial base that can make a chip with similar methods to the 1980s at scale, or whether they just need to create a single chip as the culmination of all their work. It also depends on how slow you're willing to go -- with enough RAM, you could emulate the 8086 on something like a 4004 at a slower but still usable speed. (C.f. ARM Linux running on an 8-bit micro[1]) If it's a single chip, they can do things that don't scale. Using a simpler processor increases yield dramatically, making it easier for them to get a working processor later. Corrosion might be a problem if they take a long time to build things, but they can use gold wiring for everything despite the cost. If you imagine them as monk-scribes, I think a story could be made of them practicing and honing their craft 12 hours a day until they can hand-etch circuits using a microscope and mechanical tools to downscale each movement they make (Sidestepping the UV source for photlithography). The RAM requirements can be lowered by micro-weaving readonly data with rope-core memory in a tiny package. Humans are surprisingly good at fine and accurate work. This would be an illuminated Bible or sand art, but at an unprecedented scale. The biggest hurdle, I think, is the energy required for getting chemicals at high purities and performing vapor deposition. Maybe they could harness hydro power to generate electricity? Maybe they can burn coal or charcoal for heat? The wear on such a system might be too much to keep up with for them.

[1]: http://dmitry.gr/?r=05.Projects&proj=07.%20Linux%20on%208bit

It wouldnt even be hard emulation in a strict sense of the word. 8086 itself is microcoded. Anything from https://3.14.by/en/read/homemade-cpus will be able to run equivalent microcode. https://gigatron.io/ is about 1000 transistors/diodes, totally doable by hand if you are crazy enough.

You forgot the "create the universe" step.

God would take care of that during the first six days.

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