Comment by backpropaganda | Hacker News Reader

Comment by backpropaganda | Hacker News Reader

Parent Full thread

This is a deterministic program we're talking about. Once it behaves correctly in the test vectors, it has to behave correctly with real vectors. There is no distributional difference between test vectors and vectors from the API.

Reply to Smaug123: The brain is mostly deterministic. Quantum-level nondeterminism has very low probability to matter much.

The brain is likely to be very debuggable. Even today, we continue making progress figuring out more and more things about it. If we had designed the brain, we would know its functioning almost entirely.

You know that we can understand smaller animal brain very well now, right? There are projects going on right now which aim to perfectly simulate a worm's brain. We didn't even design a worm's brain, and we would design the AI and know all its evolution principles, and have infinite access to all its internals (which we don't have with the human brain).

Reply no. 2:

Since you guys down-voted me for disagreeing with your prophet, HN rate-limited my ability to comment.

It's quite a lot easier if you reply to a comment using the reply features of HN; that way I don't have to check the parent comments of my own comments.

"Knowing the functioning of something" is nothing like the same as understanding why it does what it does. I work on a large operating system, which was designed by humans; it takes many days to find the root cause of bugs. I have the best access it's possible to get to that operating system, and it still takes a large amount of time to even detect that there has been a bug, let alone determine why it happened and fix it. That amount of time to detect a bug could be lethal in the case that the bug arose in a superintelligent being.

"Since you guys downvoted me for disagreeing with your prophet, …"

That deserves a downvote. Please consider that people might have downvoted you because they believe that what you're saying is wrong; not for any meta-reason.

> The brain is mostly deterministic. Quantum-level nondeterminism has very low probability to matter much.

Sources, please?

At an atomic level, events are not deterministic.

At a molecular level, events are not deterministic.

Perhaps you are referring to parts of the brain that are not made of atoms?

Personally, I suspect that the brain is entirely non-deterministic in terms of the material it is made of and fine-grained behaviour [because physics and chemistry support that idea].

But I suspect the brain's structure does something to offset this at the larger scale, and make it more predictable/deterministic (averaging, wisdom of crowds, etc). However, I do not assert the latter as fact, merely my own speculation.

At an atomic level, events are not deterministic.

At a molecular level, events are not deterministic.

Therefore, we all behave randomly. Qed.

It's controversial at best that atomic-level physics is non-deterministic.

http://scienceblogs.com/interactions/2007/06/08/on-quantum-m...

"The probabilities are what they are, no matter what we want, no matter what we visualize, no matter what we meditate upon while imbibing inspirational substances. It doesn’t matter how much you want that electron to be spin up, it doesn’t matter how many good “vibes” you give the electron about being spin up, it always has exactly a 1/2 chance of being spin up, a 1/2 chance of being spin down."

Sigh. http://lesswrong.com/lw/r5/the_quantum_physics_sequence/

Even if the evolution rule is deterministic, it's still epistemically/indexically nondeterministic from the perspective of the observer.

Quantum events in the brain would decohere almost immediately, leading to effectively nondeterministic behavior at any scale above the cellular. The philosophical determinism of wavefunction realism (which is the LW argument) is irrelevant to the actual behavior.

> At an atomic level, events are not deterministic. > At a molecular level, events are not deterministic. > Therefore, we all behave randomly. Qed.

This doesn't follow. The combination of many random events can be highly predictable.

Tossing a fair coin is random. Combining 10000 coin tosses will give you a result close to 5000 heads and 5000 tails, and I can predict you won't get 4000 heads and 6000 tails or 100 heads and 9900 tails.

So there's various types of randomness, and the more you average out uncorrelated events the more you get something very close to a predictable result.

Example via A. Einstein:

http://userpages.umbc.edu/~dfrey1/ench630/ein_ran_walk.pdf

In your opinion, is there even the slightest chance that the brain is deterministic in its operation? If so, how debuggable do you think the brain is, even in principle and given access to nanotechnology to monitor its state?

Reply on news.ycombinator.com