A thought experiment!
Bitcoin can be mined using paper and pencil.
In an apocolyptic future, where we've all nuked each other (WW3), rising sea levels have destroyed major cities, and a massive solar flare destroys the majority of electrical equipment / data centers / transformers, there will surely (hopefully) be some communities left to carry the torch.
There won't be any chip manufacturers, books, much civilisation to speak of. However there will surely be some preppers who dust off their USBs in Faraday bags, and start to teach their children about Bitcoin before all their circuitry rots into the dusts of time.
Presuming this 'de-progress' takes place over several years, meaning hashing can continue whilst the difficulty adjusts (radically) downward, how will the bitcoin network proceed?
How might new blocks be created (without electronic computers or telephony networks) and distributed to "miners" in other communities?
How would the mempool be handled?
How might the rules (such as 21m cap) be enforced?
5k sats for the best answer :-)