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Comment by diminoten | Hacker News Reader

What you're saying is merely postulation, it's not "demonstrably" true, not to mention your use of the term "impractical" is probably the most misleading use of that word I've read today.

You're writing off thousands of years of philosophy and dozens of years of experimental results in maybe a paragraph, if I'm being generous.

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It actually IS demonstrably true that the brain is made of atoms. That makes it a quantum system, which our modern physics tells us how to simulate. The use of the term "impractical" here refers to the fact that we don't have quantum computers and that we don't have the computing power required to simulate such a large quantum system.

I'd say dismissing thousands of years of philosophy here is relevant, since it was likely produced before we had the tools to understand what we're dealing with. All experimental physics points towards an understanding of how quantum systems work, and that's all we need to model any quantum system. The brain is not any different because it's a brain.

quantum theory is a hypothesis. perhaps it's the best one so far for what the brain is made from. but it's truth is only as demonstrable as this: it's not yet been falsified.

You can say the exact same thing about any scientific model. My view on this has always been that as long as the model accurately predicts experimental results, assume it is correct for your calculations until it is proven to be wrong.

Even then, we never stopped using classical mechanics even though they were proven to be wrong at a variety of scales. They just happen to very closely approximate reality in some contexts and are useful.

The fact of the matter is, we have tools that are correct as far as we know and they point towards thinking that every quantum system is computable. Until this has been proven wrong, the fallacy is believing the brain is different, not the other way around.

Theories not only have to predict outcomes of events, they must also be falsifiable (and must expand on something thus far unexplained by other theories, you can't just recreate gravitational theory, for example).

You are, by your own admission, working with an incomplete understanding of how a scientific model functions. So I ask you, why should you be even commenting on this topic? Why should anyone take what you have to say seriously on this specific topic?

So no one should be commenting on this topic unless they have a perfect understanding of scientific theory? That seems terribly counter-productive.

I'm commenting on this topic to share my opinion and, to the extent of my knowledge, try to explain why I believe someone else's reasoning is flawed.

Now if you believe my reasoning is false, you're free to call that out. You're not free, however, to dismiss my contribution to the discussion simply because I'm not operating under perfect understanding of a field that isn't mine.

Call it out, explain why, participate in the discussion, and drop the personal attacks. I think at least part of my point is valid, even after what you pointed out.

I'm pretty sure I am free to dismiss your contribution "simply" because you don't know what you're talking about.

But let's not get caught in the weeds here; I don't think you're correctly conveying the level of certainty with which we understand quantum mechanics. There's a ton we don't have the slightest idea about in this area of science, so let's not forget that.

Quantum theory is a "hypothesis"? The entire foundation of modern electronics is based on quantum theory. It's something that has been tested over and over in labs and the regular world for over a century.

It's been tested and proven FALSE, just look at relativistic effects. We just don't have anything better.

You're confusing hypothesis with theory. Hypothesis is a proposed explanation that can be tested (i.e. is falsifiable). Theory, on the other hand, is a hypothesis that has undergone extensive testing and has been proven to be a plausible explanation for observed phenomena. Quantum mechanics has undergone rigorous testing, and has proven time and time again that it can accurately explain many of the properties of our universe.

Yes, the brain is made up of atoms, but our modern physics does not, at least not with the degree of certainty you're waving about, tell us that it is therefore, necessarily, simulatable.

I believe this to be the case, and there is some evidence that this is the case, but it is not anywhere near as certain as you're claiming.

As for your word choice re: impractical, the word shouldn't be used in place of 'impossible', which is the correct word you're looking for.

> What you're saying is merely postulation, it's not "demonstrably" true

I don't think the parent disagrees with you. The question of whether or not something is _computable_ in the technical sense of the word does not need any sort of demonstration or experimental results.

Actually, when we assume that any particular physical system is computable, that's exactly what it is - an assumption, there is currently no strong evidence that all physical systems are computable, and despite the fact that it seems most people (including experts) believe that they are, it's still usually considered an open question.

> Viewed from the right angle, the CTD Principle still is shocking. All we have to do is look at it anew. How odd that there is a single physical system – albeit, an idealized system, with unbounded memory – which can be used to simulate any other system in the Universe!

http://michaelnielsen.org/blog/interesting-problems-the-chur...

> You're writing off thousands of years of philosophy and dozens of years of experimental results in maybe a paragraph, if I'm being generous.

I'm not the parent poster, but I'd like a citation re: experimental results. What are you saying exactly?

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