What makes you claim that? I have not seen proof of that (on the contrary, we don't have smooth emulation of animal like movement yet, which brains figure out pretty fast)
The question is, what evidence is there that the most simple structures we can call brains are doing something which is fundamentally impossible to do with something other than a brain.
Given that brains are fundamentally governed by the same physical laws as everything else, there shouldn't be anything about them which cannot be replicated in some way by something sufficiently capable of emulation of their processes.
That's not to say it's simple. Just that brains obey the laws of physics, and as long as that's true, they should be able to be replicable.
Unless your contention is that brains are somehow able to operate outside the constraints of the laws of physics, in which case we're going to have a fundamental difference of opinion as to the nature of the universe and whether things with brains are particularly special.
This 3 pounds of meat between my ears is certainly special (perhaps the most complicated thing in the known universe) but it certainly not magical.
Just because something is non-magical doesn't mean it can necessarily be simulated by a computer, especially a practical computer that we can actually build given our level of technology and available resources.
I know you mean today, but what about in 100 years?
There are still physical limits to computation, even if we had godlike powers to rearrange the universe as we like (Bremermann's limit, Landauer's principle, there are probably others but I'm not a computer scientist or physicist). More practically, the mass and energy we have to build and operate computers with is finite. Until we know what principles the brain actually runs on, we can't do the math to determine if its physically possible to build computers that simulate it.
That said, if we find it uses some new principle that we don't exploit in our computers, things get very exciting because then we can start trying to do that (you see a faint whisper of this in the excitement around quantum computing).
I mentioned this elsewhere, but encryption is a great example: other than the breakthrough of another sort (like quantum computing), we can easily come up with a key size that is exponentially harder to compute solutions for compared to computing power increases we can achieve. In a 100, 1000 or a million years.
What if the problems we need to tackle are of a similar complexity? Do we ever get there?
We are all holding our breath for both fusion and quantum computing, and while we know they are theoretically possible, will we ever make them practical?
"Able to be replicable" is a far cry from being practically replicable.
We are unable to get two biologically identical (or at least extremely close) brains of identical twins to develop in the same way, let alone two distinct brains, or a simulated version of a brain.
The claim is potentially equivalent to a claim that since universe is theoretically computable, we'll eventually be able to simulate it.
Not at all. I'm not saying we actually will simulate it, just that it's got the property of theoretical simulatability. Which means there's not anything magical going on under the hood. Which means consciousness isn't magic.
"What can be processed" to me implied practical utility. If you did not mean that, thanks for the clarification.
Still, to me the fact that it could be theoretically achieved with computers is not very useful if it can't be achieved practically, and that certainly makes "biological" computation different from synthetic computation.
i would rather ask one to think, what evidence is there that we cannot do brain on non-gooey stuff?
If i take every atom/molecule from one brain (assume a snapshot in time) and replicate it one by one at a different location, and replicate the external IO (stimulus, glucose...), what evidence do we have that this won't work? likely not much
Now instead of replicating ALL the atoms/molecules exactly, I replace one of the higher level entities like a single neuron with a computational equivalent - a tiny computer of sorts that perfectly replaces a neuron within the error bars of the biological neuron. Will this not work? I mean, will it not behave in the same exact way as the original biological brain with consciousness? (We have some evidence that we can replace certain circuits in the brain with man-made equivalents and it continues to work.)
You know where I'm going with this... FindAll, ReplaceAll. Why would it be any different?
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If i had to argue that it wouldn't be the same, here's a quick braindump off the top of my head:
- some entities like neurons literally cannot be replicated without the goo. physics limitation? but the existence of the goo is a proof of existence. but still, maybe the goo has properties that cannot be replicated with other substances
- our model of the physical world has serious limitations. on the order of pre-knowing-speed-of-light-limitation. maybe putting the building blocks together does not create the full thing. maybe building blocks + magic is needed to create the whole.
- other fun limitation of our physical model
This is actually not that true, what exactly are you saying with "replaced certain circtuits in the brain with man-made equivalents and it continues to work"? I'm certain I never saw something "man-made" like that used to "replace circuits in the brain" and it "continuing to work", in fact this would probably get a nobel for the creator if this was really proven.
Also, we don't have evidence that the processes in the brain are replicable at all, if for example Penrose's theories are correct (or any other non-reductionist that accepts the need for local identity and/or metaphysical properties for the consciousness). You need to assume A LOT of things in order to get this theory some credit, and many things we are literally unable to explain (like consciousness itself) should be reduced to those assumptions in order to make it work (for example, you must assume that is not the gooey stuff that gives rise to the consciousness in the first place, that it does not need very extremely specific conditions to exist, and so on). This line of thinking is kinda dangerous.
Note that I was responding to a comment claiming:
> What you really mean is is there any meaningful difference in what can be processed by biological computing and non-biological computing.
> The answer to that would appear to be, no.
> i would rather ask one to think, what evidence is there that we cannot do brain on non-gooey stuff?
I don't think this should stop us from trying, and it's pretty obvious it won't. But there is no proof either way — potentially the problem is so complex that we never get there in practice?
(Also note that proving a general negative statement is pretty tricky and usually avoided — we usually look for counter-examples, evaluate a full finite/countable set of scenarios, etc)
Another point I'd add is that we've already got practical examples of computations that are especially hard for computers to practically do even if they are "obvious" in theory — we use those as a base for encryption, for instance.