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Ray Kurzweil does not understand the brain

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Re: Ray Kurzweil does not understand the brain

#201

Post by joe_the_user »

btilly wrote: post #165
api wrote: post #152

Earlier quoted context omitted.

Where that falls down is that it fails to consider limits. Exponential growth cannot continue forever. At some point, something will limit it. It may be a physical limit, a supply-side resource limit, or an economic demand limit, but there will be a limit somewhere. Without limits, a single bacterium could fill the entire universe in a few years. Sometimes things do grow like that for a while, but Kurzweil's attempt…

True. However decades long periods of exponential improvement in technology is the norm, not the exception. The most spectacular example is Moore's law, but it is hardly alone. If you read The Innovator's Dilemma you will find plenty of other examples, ranging from the maximum range of a steam ship to the volume of dirt a backhoe can scoop per hour. The interesting questions are how much computing power you need to p…

The idea of "things leveling out" evoke a metaphor of there being some finite amount of resources that can be gotten out of somewhere.

Exponential growth of tools opens up an exponential number of different avenues of exploration - if computers didn't advance at all for ten years, we'd still come up with many more ways to use them. With them advancing exponentially, we can not only find different ways of using them but new fields where different forms of exponential growth can happen. And so-forth. There's no fixed frontier but a moving process.

This isn't saying it's all wonderful but it's all likely to be a bit beyond our ability to encompass it - to draw a circle around it.

Re: Ray Kurzweil does not understand the brain

#202

Post by cageface »

TheEzEzz wrote: post #200
cageface wrote: post #192

Earlier quoted context omitted.

The essential point is that you can't model the behavior of a non-equilibrium system by modeling its constituent elements, which is what Kurzweil claims. That no two non-equilibrium systems are exactly alike seems to me a different question.

I do computational fluid dynamics for a living. I assure you, we model non-equilibrium systems all the time.

You should have the math chops to read the papers then, which make the point better than I can.

Re: Ray Kurzweil does not understand the brain

#203

Post by werrett »

api wrote: post #85
jasongullickson wrote: post #74

Earlier quoted context omitted.

Getting close would take an advancement in computer technology of the magnitude of the transition from vacuum tubes in individual boxes to a 32nm Core i7. ...so about 35 years? ;)

Maybe, though I am concerned about processing power stagnating. Advancement is governed by economics as well as technical capability. There must be demand for new technology, or a field stagnates. Witness aviation as an example... utterly stagnant outside of military niche applications. People seem to no longer want faster and faster computers, and the market seems to be moving toward lighter-weight lower-power porta…

You're confounding peoples preference for usability (including portability) with a preference for applications with low computational demands.

If you could pack the "extreme gamer" capabilities of a Playstation or an Xbox into a format as "usable"[1] as an iPad... Then you would of engineered the next iPad.

The iPad was able to come into existence because we've finally hit the point where we can cram that much computation into a small factor form (along with all the other engineering advances like wireless networking, reducing power consumption, improving display and improving battery life).

Most of those advances are directly descended from the pushing of the bleeding edge. Companies / people are not simply going to go "oh we've got iPads now. So no need to make anything faster / better / bigger".

[1] By usable I'm not talking about some magical Jobsian property of the device. I'm not even talking about the software interface. I'm talking about being able to surf the web / post to your blog / whatever while on the toilet. Try doing THAT in 1995.

Re: Ray Kurzweil does not understand the brain

#204

Post by demallien »

ewjordan wrote: post #112
api wrote: post #65

I'm a life-long programmer who presently works in software, but I studied biology in college... mostly because I wanted to learn about learning by studying how living systems do it. Biological systems are nothing like anything we would ever engineer, and to understand them we must remove our "anthropocentric engineer goggles" and look at them for what they are. Analogies between biological systems and computers, soft…

DNA is not a program-- it is a molecule, and one that may very well do things at the quantum level that are biologically important. Sure, but Kurzweil's claim is merely that if DNA can encode everything the brain does with N bits of information, then regardless of how the DNA behaves, we have at least a loose estimate of the level of complexity in the brain. I don't necessarily think that he's right that AI will firs…

if DNA can encode everything the brain does with N bits of information, then regardless of how the DNA behaves, we have at least a loose estimate of the level of complexity in the brain.

No even close. Imagine a kilobyte filled with alternating zeros and ones. We have two commonly used methods for describing the information content of this kilobyte. Shannon information content is closely approximated by today's compressors - and 1k worth of alternating zeros and ones compresses to next to nothing. Kogorov Complexity is the length of the minimum necessary program to produce the 1k worth of zeros - again, a simple loop, incrementing a pointer then dereferencing the pointer to fill the address with alternately a zero or a one suffices - a mere handful of bytes are necessary.

Now imagine that the RAM chip holding the zeros and ones is hit by a bunch of cosmic rays , flipping about 10% of the bits. Both the size of a compressed version of the new kilobyte, and the Kogorov program to generate the new sequence are both going to dramatically increase in size.

Now, the thing is that DNA produces a brain to a fairly homogenous pattern - it's the equivalent of my series of alternating zeros and ones, although admittedly it's a bit more complex than that - this is to be expected, there's more Shannon information in DNA for encoding a brain than there was in my simple pattern of zeros and ones.

The cosmic rays are the equivalent of a brain learning, encoding information by weighting connections between neurons. This process massively increases the amount of information stored in a human brain, but this information must be copied if you actually want the copy to behave like the original. I would expect this amount of information to be several orders of magnitude bigger than that found in the DNA, which is why Kurzweil's claim is just completely off the wall.

Re: Ray Kurzweil does not understand the brain

#205

Post by jacquesm »

glenra wrote: post #197
pjscott wrote: post #167

Earlier quoted context omitted.

The problem here is that an adult brain has a much higher Kolmogorov complexity than the DNA that codes for its parts. http://en.wikipedia.org/wiki/Kolmogorov_complexity

Sure, and a shag rug has a much higher Kolmogorov complexity than the instructions for how to weave it. If measured carefully enough you'd find every individual strand of yarn in it has a unique length, orientation, curvature, amount of twist and amount of fraying that can be measured to an arbitrary degree of precision. So if you wanted to reproduce or store a description of that exact rug, you couldn't do it. That…

There is a huge part missing here though. A rug simply has to 'be', a look alike will suffice. A brain has to work.

Re: Ray Kurzweil does not understand the brain

#206

Post by jacquesm »

10ren wrote: post #184
jacquesm wrote: post #132

Earlier quoted context omitted.

Or 500, or 10,000, who is to know. The problem is that the way the brain seems to be organized is around very simple (at face value) processing components that operate at a ridiculously low frequency in a massive parallel manner that we programmers can only dream of, at a power budget that would make Ebenhaezer Scrooge look very happy indeed. If 35 years (according to Henry Makram, linked below it's only a decade) wa…

The "simulate at reduced speed" theory appeals to me, but I think the actual numbers make it implausible. Assuming Moore's Law, 30 years is a 1,000,000 speed up, plus let's say 4.5 years for 3 more doublings, giving us 8,000,000. To simulate 1 second would take 3 months. Debugging would be frustrating. (assuming 35 years from now; seems an arbitrary figure.)

> Assuming Moore's Law

That alone may already be a mistake, it's an observation, not a law after all.

Besides, compared the 35 years ago we can now do things 1,000,000 times faster than back then, but computers are not 1,000,000 times 'smarter' they just give the same answers that you could compute back then but faster and on fewer computers.

The future is parallel anyway, so it isn't Moores law (increase in density of transistors on-chip) per-se that will drive this, more likely there will be a switch to increasing chip packing density with smaller chips (bigger yield) and better communications between the chips (think computing fabric).

We need a huge advance in programming languages before we can really contemplate building an AI by taking advantage of such a structure though, simply simulating the organic soup that forms a brain is going to be a much harder problem computationally and may simulate a dead or an insane brain much more easily than it will simulate a live and thinking one.

Re: Ray Kurzweil does not understand the brain

#207

Post by jacquesm »

barmstrong wrote: post #143
jasongullickson wrote: post #74

Earlier quoted context omitted.

Getting close would take an advancement in computer technology of the magnitude of the transition from vacuum tubes in individual boxes to a 32nm Core i7. ...so about 35 years? ;)

This is exactly what I was thinking. Actually, if that last shift took 35 years, the next one of that magnitude will be even faster. This is Kurtzweil's fundamental insight: exponential growth is faster than people realize. We consistently underestimate it because our brains are pre-disposed to think linearly. If it takes you 1 year to solve 1% of a problem, your brain feels like you're 99 years away. In reality, you…

You can solve a problem 1% in 1 year if it is a linear problem then you are right. But if the 1% was the easy bit and the 99% remaining are very hard then you still don't have a solution.

If the solution is 99% easy and 1% hard then you may find out after completing 99% of the problem.

Many problems are like that, simulating the brain is an excellent candidate for being such a problem. If it was just a matter of throwing more computer power at it then we'd have solved it years ago, it's that big a prize. But there is still a large part of our understanding missing and understanding does not yield to Moores law.

Re: Ray Kurzweil does not understand the brain

#208

Post by jacquesm »

api wrote: post #104
SMrF wrote: post #92

Earlier quoted context omitted.

"I think it's now possible with a big rack of multi-core machines in an MPI cluster to approach the capabilities of a fruit fly's brain." This seems so unlikely. Isn't it more likely that it takes a rack of multi-core machines to simulate a fruit fly's brain using our extremely primitive algorithms for approximating intelligence? In other words, it's a software problem.

You're right. It's a software problem and a hardware problem. Our hardware is not up to the task, and even if it was we wouldn't know how to program it. Evolutionary computation and non-von-Neumann architectures such as stochastic data flow architectures might be where to start. We would not write the code. We would build the right kind of architecture and then evolve the code within that architecture.

> We would not write the code. We would build the right kind of architecture and then evolve the code within that architecture.

That sounds more like an approach that I think would produce results.

The key here is 'right' though, what is right?

Re: Ray Kurzweil does not understand the brain

#209

Post by jacquesm »

Estragon wrote: post #162
zoomzoom wrote: post #161

Earlier quoted context omitted.

Look - all the talk of the brain as a "quantum computer" seems to be more full of "bull" than the talk of mind uploading and 700 year lifespans. Quantum interactions happen in all matter that we observe, so they happen in the brain. There is not that much more to it. Neural computation depends on neurons and synapses, communicating with hormones and electrical impulses. If we can model the significant algorithms and…

As far as I know, Roger Penrose first proposed the idea that quantum effects on neural processes will make computational modeling of said processes impossible. It is highly speculative, and the strongest evidence it's got going for it is that an eminent physicist wrote a book based on it ( The Emperor's New Mind. )

The Emperors New Mind is an excellent primer in physics but it failed to sell the quantum idea of the brain in a convincing way.

I expected a rather stronger argument, especially from someone as high up in the hierarchy of science as Roger Penrose, and after laying such a huge foundation.

Maybe there is one but if there is I haven't found it in that book.

Re: Ray Kurzweil does not understand the brain

#210

Post by zasz »

jerf wrote: post #100

There's a psychological principle that I've forgotten the name of that observes that by setting the stage correctly you can cause people to accept assumptions without even thinking about it by framing the debate correctly. This conversation here on HN is a great example of that. Simply by the way the article is written, it is being taken nearly as fact by most participants that a human-scale AI simulation must work b…

Possibly http://en.wikipedia.org/wiki/Anchoring.
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