This problem is hard. Extremely hard. But that does not mean that it is not theoretically possible (if very, very, very unlikely). A lot of the brain uploading

This problem is hard. Extremely hard. But that does not mean that it is not theoretically possible (if very, very, very unlikely). A lot of the brain uploading people seem to look at this through destructive brain scanning (correct me if I'm wrong). That sounds like a terrible idea - why does it have to be all in one go and not reversible. What if - for example (I'm spitballing) - you move into the brain slowly replacing each live neuron with an artificial neuron (far fetched I know - nanotech is ridiculously hard/difficult), instead of going slice by slice on a frozen brain. There is no reason that this slow "viral" method couldn't be done (or reversed - replace artificial neuron with neuron). This is akin to how we deploy distributed systems - create a compiled slug and push it out node by node via bittorrent. The change is tested on each node, and slowly moves out. If anything goes wrong - just roll back to previous slug. Once you have full conversion - upload away (as I presume getting states of artificial neurons is relatively easy vs. organic cells). Have no doubts about it - this is a super hard problem. But it is not impossible.