Aside from the fact that the sheer complexity of the problem means that it likely will never be solved (if the three body problem is difficult, the hundred-trillion body problem is incalculable in practice), there's another fatal flaw in the "mind upload" schoolboy fantasy. The assumption is that the "mind" is merely the sum of neuronal connections and their relative weightings in terms of inhibiting or exciting electrical transmission. But this is false. Most of what happens in the brain is intimately connected to our sensory system. Devoid of a body, the brain does not function properly. People immersed in full sensory deprivation tanks begin to hallucinate after a few hours; the effect of sensory deprivation lasting longer than this is unknown but almost certainly catastrophic. Now one could argue that computers could simulate sensory inputs, but now we're piling absurdity upon absurdity. And as for the egocentric idea that by uploading a "mind" the person achieves immortality - the copy argument made in this article is exactly right. One no more achieves immortality in this way than in creating a clone. The only difference: clones are achievable; mind uploads never will be.