[danvasquez29]

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.

[jstanley]

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.

[xjwm]

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.

[hawski]

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

[saagarjha]

It will just take a long time, though…

[jstanley]

Naturally, but the original question was how long.

[hawski]

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.