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Showing posts with label ai. Show all posts
Showing posts with label ai. Show all posts

Tuesday, November 23, 2010

Here's a fun quote about AI

JORDAN POLLACK
Computer Science and Complex Systems Professor at Brandeis University

A persistent belief is that human symbolic intelligence is the highest form of intelligence around. This leads directly to both creationism and good old-fashioned AI which seeks to model cognition using Lisp programs.

Evolution can design machines of such great complexity that the space shuttle with half a million parts looks like a tinker toy construction. In order to explain the design intelligence of evolution, most Republicans are convinced that a superintelligent creator was involved. Developmental intelligence which manufactures machines with 10 billion moving parts without any factory supervisors is another area where nature outstrips the best human performance. Immunological Intelligence, telling self from non-self, is another AI-complete problem. And human intelligence itself is so vastly complex that we've made up stories of conscious symbol processing, like logic and grammar, to try to explain what goes on in our heads.

The mind, like the weather, envelopes the brain like a planet and requires dynamical and integrated explanations rather than just-so stories.


from a fascinating thread over at http://www.edge.org/3rd_culture/thaler10/thaler10_index.html by way of http://www.marginalrevolution.com/marginalrevolution/2010/11/richard-thalers-question.html

Saturday, November 7, 2009

I just finished reading Goedel Escher Bach

GEB alternates dialogues and essays on the author's staggering range of fixations and obsessions in which Hofstadter adds his own remarkable insights and comparisons on topics including music, art, mathematics, genetics and philosophy. GEB's sprawling nature follows tangled paths but eventually loops back to the question of intelligence, souls, free will and self-awareness.

The unorthodox structure is what sets the book apart, but the braiding of ideas may lead to a takeaway of: "Ok, that's interesting, and you're clever, but what is the chief takeaway here?"
This is a common criticism which led led Hofstadter to author the psuedo-sequel "I Am a Strange Loop" (which I haven't read), in which he distills his arguments more directly and concisely (and personally -- he imagines a low-resolution "simulation" of his wife's mind within his own after her death).

Anyone who completes GEB comes away with an honorary computer science degree, as there's a heavy focus on computability theory, data and data structures, natural language processing, AI, recursion, memory, hardware, software, all under the guise of philosophy and investigating what gives rise to self-awareness and intelligence.

On top of this, the GEB reader receives an introduction to the art of Escher, Magritte, Bach, John Cage, as well as some basics of neuroscience, boolean logic, zen philosophy, number theory, music theory and molecular biology.

Although the number theory and biology chapters dragged, I was fascinated by the discussion of the Goedel incompleteness proof and the implications it had for the mathematics community at the turn of the century. There is also a fascinating section on AI that starts with Turing tests and pattern recognition and ends with the remarkable conclusion that a truly AI may be terrible at all the things that people may struggle with as well, such as rapid computation or chess playing.

At the least, GEB presents a multitude of ideas and food for thought. At its best, it instills lucid notions of how our minds work and what gives rise to life, language and intelligence.

Sunday, July 19, 2009

Smack talkin' D.R. Hofstadter delivers sick iceburn on R. Kurzweil

This is a profound interview with Douglas Hofstadter, author of Goedel Escher Bach and I Am a Strange Loop.

Money Quote/Excerpt:

I think Ray Kurzweil is terrified by his own mortality and deeply longs to avoid death. I understand this obsession of his and am even somehow touched by its ferocious intensity, but I think it badly distorts his vision. As I see it, Kurzweil's desperate hopes seriously cloud his scientific objectivity.

...Kurzweil sees technology as progressing so deterministically fast (Moore's Law, etc.) that inevitably, within a few decades, hardware will be so fast and nanotechnology so advanced that things unbelievable to us now will be easily doable. A key element in this whole vision is that no one will need to understand the mind or brain in order to copy a particular human's mind with perfect accuracy, because trillions of tiny “nanobots” will swarm through the bloodstream in the human brain and will report back all the “wiring details” of that particular brain, which at that point constitute a very complex table of data that can be fed into a universal computer program that executes neuron-firings, and presto — that individual's mind has been reinstantiated in an electronic medium...

Rather ironically, this vision totally bypasses the need for cognitive science or AI, because all one needs is the detailed wiring plan of a brain and then it's a piece of cake to copy the brain in other media. And thus, says Kurzweil, we will have achieved immortal souls that live on (and potentially forever) in superfast computational hardware — and Kurzweil sees this happening so soon that he is banking on his own brain being thus “uploaded” into superfast hardware and hence he expects (or at least he loudly proclaims that he expects) to become literally immortal — and not in the way Chopin is quasi-immortal, with just little shards of his soul remaining, but with his whole soul preserved forever.

Well, the problem is that a soul by itself would go crazy; it has to live in a vastly complex world, and it has to cohabit that world with many other souls, commingling with them just as we do here on earth. To be sure, Kurzweil sees those things as no problem, either — we'll have virtual worlds galore, “up there” in Cyberheaven, and of course there will be souls by the barrelful all running on the same hardware. And Kurzweil sees the new software souls as intermingling in all sorts of unanticipated and unimaginable ways.

Well, to me, this “glorious” new world would be the end of humanity as we know it.


Hopefully you're hooked by now, so read the rest!

Thursday, July 16, 2009

Loblaw's law

When you have numbers that are really really really big, you can stop talking about probabilities and start talking about laws.

Statistics are often unintuitive for people, and the Monty Hall Problem is a famous example of that un-intuition in action.

And of course, as humans, we distrust machines. And statistics are, so far, the best tool machines have for imitating humans in areas such as language and vision. How we hate these machines, with their statistics.

Yes, so if you are a human reading this, you may feel a certain amount of smugness knowing that language is a built-in feature for you; you can read an article and comprehend with absolute certainty its key points and discuss it in an intelligent and natural way. Even if a computer were able to analyze the same article, it could only offer up soulless suggestions of meaning with varying degrees of certainty, and with little or no actual intelligence.

But as it turns out, you and I live in a crazy universe not governed by laws so much as statistics.

Mandatory Djikstra quote: The question of whether a computer can think is no more interesting than the question of whether a submarine can swim.

On their own, atoms can be in several possible states, each with varying probabilities, where the most probable state has lowest energy.

With more heat added to a closed system such as a gas, the likelihood that each atom is in a higher energy state increases. Each macro state view of the entire system is equally likely, keeping in mind that particles are coaxed from lower micro energy levels with likelihood directly linked to the work performed on the system. All arrangements of molecules in the container are equally likely and they are all interchangeable with one another.

Now if you were to take each of these equally likely macro energy states and group them in buckets by total energy level of the system, the distribution would produce a bell curve. So, looking at this bell curve, you could state with some amount of certainty the likely range of energy (temperature actually).

EXCEPT, that's not how the universe actually works!!

The contradiction arises because the number of particles is on the order of 10^23.

So there's still a bell curve, but it's not really a curve so much as an extremely tall spike with almost zero width and almost no variance. Temperature and entropy and the first and second "laws" of thermodynamics all work because 10^23 is an enormous, enormous number, and the expected value (the center of the curve) is the only value anyone actually ever experiences.

To illustrate I'll create a law right now, named after a brilliant attorney, called Loblaw's law. Loblaw's law states that it is not possible to flip a (normal) coin 10^23 times and produce only heads each time. You may say, well technically that is still possible, so how can it be a law?

Well, technically it is (sort of) also possible for the entropy of the universe to decrease for a few minutes. Technically, it is also possible that heat could flow from a cold object to a hot object. Technically, a broken egg could assemble itself from the floor and leap back into my hand...blah blah blah, Loblaw's law is a law because these events are so unlikely that it they will never happen.

That's the way it goes with ginormous numbers, and that's why we can call them the laws of thermodyamics, although a better name for the field is actually Statistical Mechanics.

Back to computers, the point is that statistics is a strength, not a weakness of computers which may perform natural language processing, image recognition, or other tasks wherein humans naturally have the upper hand. Feed a somewhat sophisticated AI a few petabytes of salient data and I believe suddenly that Dijkstra quote will ring true.