Comment by vidarh

Unless there is unknown physics going on, we have the existence proof for the possibility of a compact computational device capable of accurately replicating the thought patterns of a human in the form of every single human brain. That, to me, makes it highly improbably that we won't be able to replicate it at some point, not least because we know that human brains remain functional even with significant variations even with substantial amounts of damage.

So while it might well be we will need new architectures - maybe both software and hardware, it seems highly unlikely we won't be able to.

There's also as of yet no basis for presuming we need to be "complete accurate" or need to model the physical effects with much precision. If anything, what we've seen consistently over decades of AI research is that we've gotten far better results by ditching the idea that we need to know and model how brains work, and instead statistically modelling outputs.