Bitcoin without the internet, while still somewhat functional even via sneakernet, becomes dangerous to use.
If mining nodes are isolated, they each can start developing an independent blockchain. In this scenario, the fastest miner wins and has 100% control of the blockchain with less than 50% of the hashrate. When the network is reunited, and the fastest miner communicates their longest chain, it immediately wipes any blocks that anyone else had created.
Hmmm.....Good point! I read thru this entire thread developing a theoretical solution for such an occurrence and the very last post has me rethinking it through again....Now, I can see events where multiple networks would be isolated from one another creating there own chains in parallel. While all of the transactions would be legit in each chain individually, the ledger as a whole would be forked in a unique way. Due to the isolation of nodes from one another, there would be no common hashes between any two forks so maybe it would be possible to parse the blockchain once the network was restored....that's assuming there were no cross communications or purposeful attacks however.
My other thought was centered around a DAC and broadcasting electromagnetically thru HAM radio or similar analogue network and backing up the ledger on tape until the digital network was restored....
Very interesting thoughts....there are ways....but, like mentioned earlier in the thread, there would probably be bigger things to worry about than bitcoin in such a scenario.