Ray Kurzweil does not understand the brain • Hacker News Board

Re: Ray Kurzweil does not understand the brain

#151

Post by ewjordan » Tue, Aug 17, 2010, 7:18 PM UTC

jacquesm wrote: post #135

ljscharen wrote: post #117

Earlier quoted context omitted.

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. The problem is that DNA is not sufficient. Organisms don't grow from naked DNA in a vacuum; the DNA is always contained within a cell which is enclosed within a more complex bio structure (eg…

For the moment we seem to have enough trouble modeling (relatively speaking, to the brain) simple proteins reliably. It's quite a leap of faith to make these statements about the technological future with so little in terms of progress to show in these fields for the last decades. I think the most impressive a-life demos are now almost 10 years old, the best we can really simulate is (drumroll) a cockroach. And perso…

Absolutely, I never said that I think modeling the brain would be easy (I don't) or that building it up from DNA is anywhere near the best way to attempt AI (IMO it's not).

I simply don't buy the argument that the algorithms of cognition inherit any substantial amount of functionality from their physical implementation, and hence, I see Kurzweil's complexity estimate as somewhat reasonable.

Re: Ray Kurzweil does not understand the brain

#152

Post by api » Tue, Aug 17, 2010, 7:19 PM UTC

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…

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 to turn this into a universal law and neglect limits is hand-wavey and silly.

Re: Ray Kurzweil does not understand the brain

#153

Post by bsaunder » Tue, Aug 17, 2010, 7:23 PM UTC

api wrote: post #146

bsaunder wrote: post #144

Earlier quoted context omitted.

It doesn't directly encode the structure of the brain. Development is required. Your Java program doesn't directly execute on the CPU, compilation and interpretation are required.

Totally different thing. The java program encodes each decision and computation that it performs directly.

No a Java program requires an environment to run, so does a brain .

It's just that a brain alters it's behavior and structure as a result of processing inputs (development).

We don't (normally) write Java programs to change their behavior as they process information from their environment during execution.

Re: Ray Kurzweil does not understand the brain

#154

Post by jacquesm » Tue, Aug 17, 2010, 7:29 PM UTC

ewjordan wrote: post #151

jacquesm wrote: post #135

Earlier quoted context omitted.

For the moment we seem to have enough trouble modeling (relatively speaking, to the brain) simple proteins reliably. It's quite a leap of faith to make these statements about the technological future with so little in terms of progress to show in these fields for the last decades. I think the most impressive a-life demos are now almost 10 years old, the best we can really simulate is (drumroll) a cockroach. And perso…

Absolutely, I never said that I think modeling the brain would be easy (I don't) or that building it up from DNA is anywhere near the best way to attempt AI (IMO it's not). I simply don't buy the argument that the algorithms of cognition inherit any substantial amount of functionality from their physical implementation, and hence, I see Kurzweil's complexity estimate as somewhat reasonable.

> I simply don't buy the argument that the algorithms of cognition inherit any substantial amount of functionality from their physical implementation

I'm somewhere in the middle on that. I wish for things biological to be clear-cut and deterministic enough that we can fully understand them the way we understand mechanical systems.

But precisely because the brain is encoded in precious little DNA there is some evidence that there is more to it than meets the eye, after all if 50M of gzipped data can encode the whole thing why do we have such a hard time understanding it.

There is enough repetition in there that some died-in-the-wool reverse engineer would have put 2 and 2 together by now if the secret was in the wiring or in some simple algorithm (ANNs for instance).

Apparent order appearing from chaos is a field that has seen some study and the amount of complexity that can arise form simple starting data is quite amazing, witness the mandelbrot set and other fractal forms.

It may be very hard to short-circuit such understanding and to 'divine' the workings of the formula without first going the long way around to understand the whole system rather than the 'seed' from which it grows. This is not simple mathematics where a simple equation on complex numbers gives you the mandelbrot set, it's possibly machinery interpreting an equation with 50 million terms.

In different terms, given a very distorted (dissected) picture of the 3 dimensional mandelbrot set would you be able to figure out the formula that gave rise to it without prior knowledge of the mathematics involved?

http://www.skytopia.com/project/fractal/2mandelbulb.html#epi...

Re: Ray Kurzweil does not understand the brain

#155

Post by rayval » Tue, Aug 17, 2010, 7:31 PM UTC

alisey wrote: post #140

heyadayo wrote: post #107

My programmer's understanding of the argument is this: Even if you could reduce the brain to some sort of bytecode, an interpreter is still necessary to run that bytecode. For instance, a python program might be a few bytes, but the interpreter is still a few megabytes. Yet both are necessary to run the program. Who knows how large a brain bytecode interpreter is going to be, but probably very large.

But you don't need to write the whole interpreter to understand how that small python program works.

Assuming you have the documentation, or assuming that you can extrapolate from a program in a language that you already know.

If one knows python and is given a program in APL, then likely an insurmountable barrier has been reached. If you don't have the docs the describe the language, the one can try to infer the language by running experiments on variations of the stored program. However one needs access to the processor in order to run different experiments and get different results to be able understand how the programming language works.

We don't have CPU in a form that we can experiment with ("brains in a vat"). We have a 50Mb string in APL*2, a mostly unknown language for a mostly unknown processor.

The other part is that this is not a program but a meta-program -- meaning there are multiple levels of indirection. The DNA does not directly specify the brain, but instead specifies rules for components that would eventually arrive at an assembly (guided by a rich context of voluminous other inputs over an extended period of time) that constitutes a brain.

Re: Ray Kurzweil does not understand the brain

#156

Post by nkassis » Tue, Aug 17, 2010, 7:34 PM UTC

aswanson wrote: post #60

10ren wrote: post #50

I'm not so sure about the simulation, but Ray's right that the brain cannot be more complex than the data that specifies it, speaking information-theoretically. A biologist probably wouldn't get this, because he has too much knowledge of how difficult and complex the actual translation is. It's a mathematical idea, like non-constructive proofs, which freak out sensible folk - and rightfully so. ( EDIT no offence inte…

But even looking at it in an information-theoretic way, what is being stated is that the instruction set is far more powerful than the binary analogy Kurzweil is using. The instruction I give: "Cure Cancer" has 11 bytes. But that instruction implies a ridiculously complicated set of sequences that we haven't figured out yet. In this situation, look at the genome as the instruction set for protein construction and fol…

I don't think it can be compared to instructions. More like just the startup conditions, like a rom or something. All analogies that compare computers to biological things are terrible. Mine is as much so as any other.

Re: Ray Kurzweil does not understand the brain

#157

Post by ars » Tue, Aug 17, 2010, 7:36 PM UTC

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…

No, people are talking that way because it's obvious to the participants that no one knows how to do the higher level simulation. And there is no hope of anyone figuring it out any time soon.

So people figure why not "run the program" that already exists, and that's what this conversation is about.

Re: Ray Kurzweil does not understand the brain

#158

Post by kragen » Tue, Aug 17, 2010, 7:39 PM UTC

wihon wrote: post #31

His last comment, The media will not end their infatuation with this pseudo-scientific dingbat chimes with the large majority of bold scientific claims that appear in the press. For example, not that long ago the press jumped on Craig Venter's ( http://bit.ly/uEC5 ) 'artificial cell' ( http://bit.ly/c27AL5 ), hailing it as the beginning of man-made organisms and making bold predictions about the future of life itself…

The artificial-cell experiment was pretty interesting. It demonstrated that epigenetic information is not necessary for a viable cell.

More than that, though, it's a "hello, world" — although the cell itself didn't do anything useful, now we have the compiler working, albeit expensively. Now we can do experiments like the following:

- removing introns entirely to see if that damages viability;

- inserting the gene you want at a specific place in the bacterial genome instead of splicing it in at some random place.

Basically, it's a "control group" for a much more precise set of experiments than we've been able to do in the past. It's easy to take the ability to do "hello, world" for granted as a programmer.

Re: Ray Kurzweil does not understand the brain

#159

Post by jimbokun » Tue, Aug 17, 2010, 7:40 PM UTC

arethuza wrote: post #21

mechanical_fish wrote: post #17

Earlier quoted context omitted.

It is deadly dangerous for me to watch a clip from that film. It could inspire dozens of hours of rage-filled but closely-argued physics lectures. Given the slightest provocation, I will go all xkcd.com/386 on its ass and my actual career will die of neglect. Now, I need to go calm myself by fixing some bugs before I start to throw things. ;)

For what it's worth, I was having a conversation with my son (he's 11) about the key differences between scientific and religious beliefs - I think I'll use that film as an example of how it can sometimes be difficult to tell the difference - especially when people present what are essentially religious beliefs using terminology derived from science. (NB I remember reading some Erich von Däniken books when I was 9 or…

"Erich von Däniken"

The Nova debunking of Chariots of the Gods was epic, and a important lesson to me as a high school student not to take scientific sounding arguments at face value. Also, an important lesson in not underestimating human intelligence and creativity. Most of the debunking was simply figuring out how ancient peoples did things we now think are impossible without modern technology.

Re: Ray Kurzweil does not understand the brain

#160

Post by api » Tue, Aug 17, 2010, 7:43 PM UTC

bsaunder wrote: post #153

api wrote: post #146

Earlier quoted context omitted.

Totally different thing. The java program encodes each decision and computation that it performs directly.

No a Java program requires an environment to run, so does a brain . It's just that a brain alters it's behavior and structure as a result of processing inputs (development). We don't (normally) write Java programs to change their behavior as they process information from their environment during execution.

You're confusing literal translation with development. Here's a very loose conceptual analogy:

Translation: translating Lord of the Rings into Chinese.

Development: hearing a short plot synopsis of Lord of the Rings and writing your own fantasy novel based on the same theme.

Development really does do something analogous to that. It takes a collection of proteins and rules and, through embodiment within the laws of physics, constructs the phenotype. The phenotype contains vastly more information than the genotype, and two identical genotypes will not produce absolutely identical phenotypes.

There is something fundamental about development that we do not understand. This is widely acknowledged in the developmental biology, evo-devo, and evolutionary computation fields. A closer analogy than the loose one above might be some of the behaviors we see with fractals and cellular automata, though development is less deterministic than that.

Evolution and development are somehow related. We don't quite get that either. But both processes add vast amounts of information and both involve adaptation.