I mean you can (and I have) etch your own circuit boards, but that's obviously not at the scale you need for anything other than primitive processing (70s 8-bit at MHz scale), and even then you're just looking at the next layer down (how to make your own chemical wash and get copper onto a board) as a barrier if we're truly talking about 'from scratch'.
We really depend on three things - knowledge (stored collectively and in various media eg books), materials (tools and manufactured precursor goods, available via active supply chains or existing stores), and most importantly having our basic needs met trivially so that all our time is not sucked up addressing them.
A scenario where someone has a 'wasteland' to pick over for their basic needs, knowledge and materials looks quite different to a return to primitive living where what nature provides is all their is to work with. 'if you want to bake an apple pie, first you must invent the universe' or however it goes...
Then of course there's the question of why someone would have any interest in obtaining computing power were either of those scenarios to occur. Much like the 'how do we warn future civilisations about our nuclear waste' problem perhaps it is acceptable to not bother, they'll figure it out again on their own eventually given enough time.
This stuff is fun to think about at 6am when hay fever is preventing my sleep :)
We really depend on three things - knowledge (stored collectively and in various media eg books), materials (tools and manufactured precursor goods, available via active supply chains or existing stores), and most importantly having our basic needs met trivially so that all our time is not sucked up addressing them.
A scenario where someone has a 'wasteland' to pick over for their basic needs, knowledge and materials looks quite different to a return to primitive living where what nature provides is all their is to work with. 'if you want to bake an apple pie, first you must invent the universe' or however it goes...
Then of course there's the question of why someone would have any interest in obtaining computing power were either of those scenarios to occur. Much like the 'how do we warn future civilisations about our nuclear waste' problem perhaps it is acceptable to not bother, they'll figure it out again on their own eventually given enough time.
This stuff is fun to think about at 6am when hay fever is preventing my sleep :)