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Comment by cannonpr | Hacker News Reader

I think the statement above and yours both seem to ignore “Turing complete” systems, which would indicate that a computer is entirely capable of simulating the brain, perhaps not before the heat death of the universe, that’s yet to be proven and depends a lot on what the brain is really doing underneath in terms of crunching.

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This depends on the assumption that all brain activity is the process of realizing computable functions. I'm not really aware of any strong philosophical or neurological positions that has established this beyond dispute. Not to resurrect vitalism or something but we'd first need to establish that biological systems are reducible to strictly physical systems. Even so, I think there's some reason to think that the highly complex social historical process of human development might complicate things a bit more than just brute force "simulate enough neurons". Worse, whose brain exactly do you simulate? We are all different. How do we determine which minute differences in neural architecture matter?

> we'd first need to establish that biological systems are reducible to strictly physical systems.

Or even more fundamentally, that physics captures all physical phenomena, which it doesn't. The methods of physics intentionally ignore certain aspects of reality and focus on quantifiable and structural aspects while also drawing on layers of abstractions where it is easy to mistakenly attribute features of these abstractions to reality.

Not all of physics is relevant to a brain simulation. For example, humans appear equally conscious in free fall or in an accelerating vehicle, so a simulation can probably safely ignore the effects of gravity without affecting the outcome. We also know that at body temperature (so about 310K) there is a lot of noise, so we can rule out subtle quantum effects. There is also noise from head movement, pressure changes due to blood flow, slight changes in the chemicals present (homeostasis is not perfect). We won't be simulating at the level of individual molecules or lower.

To me it seems highly likely that our knowledge of physics is more than sufficient for simulating the brain, what is lacking is knowledge of biology and the computational power.

>also drawing on layers of abstractions where it is easy to mistakenly attribute features of these abstractions to reality.

Ok - I get that bit. I have always thought that physics is a description of the universe as observed and of course the description could be misleading in some way.

>the methods of physics intentionally ignore certain aspects of reality and focus on quantifiable and structural aspects

Can you share the aspects of reality that physics ignores? What parts of reality are unquantifiable and not structural?

> Can you share the aspects of reality that physics ignores?

Here's an article you might enjoy [0].

[0] http://edwardfeser.blogspot.com/2022/05/the-hollow-universe-...

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