Just curious, we are looking into opening a mining operation ( high scale ) but according to recent news the US just missed an EMP from the sun that would have put the US back in the 18th century. In other words it would have shorted out and melted anything electronic. At that point in time or if there was an EMP attack against the US what happens to Bitcoin? Does it immediately become worthless? You won't be able to do anything with them and if stored online they won't be retrievable as they will probably be erased when all hard drives are smoked.
I know this sounds like it can't happen but it very easily can.
Even if they are wiped back to "18th century", technology from other countries would help as well as the fact that we have all of the research on or offline which would be accessible from other countries
But yet again part of the internet is hosted in the US so don't know what would happen when it comes to servers and such