Solar flare or internet destruction, any calamity that would result in bitcoin or any cryptocurrency going down is going to cause us a lot more problems than ju

Solar flare or internet destruction, any calamity that would result in bitcoin or any cryptocurrency going down is going to cause us a lot more problems than just that. No, the real existential threat to any cryptocurrency is the breaking of its hash or cryptographic algorithm. So, if someone breaks SHA-256 or ECDSA then and only then is bitcoin hosed. SHA-256 breaking would allow someone to guarantee they could mine all the blocks faster than anyone else. ECDSA breaking would allow someone to work backwards from someone's public key to their private key. Both of which are currently computationally secure, as we understand computing. If you can do those then you've basically got an Oracle and wow, that's some monumental and theory breaking power: https://en.wikipedia.org/wiki/Oracle_machine https://en.wikipedia.org/wiki/Oracle_machine