As a grad student studying artificial intelligence, it might be useful to know what exactly intelligence is.  No one can really define it.  We know that we have it.  We know that tables and chairs do not.  Everything in between is up for grabs.  I’m going to discuss what some historical views on intelligence are and what I think it might be.

The classic definition of intelligence in AI is based on the Turing Test.  This is a test created by Alan Turing to determine if something is intelligent.  You have a person and a computer in separate rooms.  In a third room is a judge.  He chats with both of them over a computer.  If he can’t tell which one is the person, then the computer is intelligent.  Basically the computer is considered to be intelligent if it can imitate a person in conversation.  If it doesn’t have this ability then its not intelligent.  This test can be extended to a more complicated task, say if you can’t tell a person and a computer/robot apart in every day life, then the computer/robot would be intelligent.

Then there are a class of people who believe that having intelligent behavior is not enough.  They say its critical what is going on to make that intelligent behavior.  Usually they say that having computer circuits create such behavior is not intelligent.  Some of them say that only having an exact human brain create the behavior is intelligence.  The classic argument from this side is John Searle’s Chinese Room.  There is a man in a room.  He receives pieces of paper with weird symbols on them.  He has a set of directions of what to do when he receives these pieces of paper, which generally involves him creating new weird symbols and passing them back out.  The symbols are Chinese and he is actually answering someone’s questions with someone in Chinese this way. Searle’s main argument is that the man does not know Chinese even though he can act like he does this way.  The room also does not speak Chinese.  Searle goes on to say that even if the man and directions were replaced by a fully accurate simulation of the human brain it would not be intelligent, you need the magic stuff of the brain to be intelligent.  Another point to make is that this example is utterly impossible, it would not be possible to create a set of directions to converse fluently in Chinese.

Another argument from a more computer science perspective is that of Simon and Newell.  They put forth the ‘Physical Symbol System Hypothesis’, which states that “A physical symbol system has the necessary and sufficient means for general intelligent action.”  They define a physical symbol system as any system which physical patterns (symbols) that are related somehow (in a system).  Basically, anything.  They later go on to say that one of the signs of intelligence is avoiding exponential search (Many problems can be reduced to searching through a space of possible solutions.  If the search space is exponential, then it is impractical or impossible to search it exhaustively.  Avoiding this exponential search requires some intelligence in deciding how to avoid it).  This is a pretty interesting idea.  I often feel that one of the key things to do to be successful is to know how much time to put into something and when its not worthwhile anymore, which seems somewhat related to this idea of avoiding exponential search.

Recently, our reading group read a paper by Ned Block that also discussed this topic.  Block is part of the camp that says that the internal processing that creates the intelligent behavior is critical to whether something is intelligent.  He provides a counter-example to the Turing Test.  A computer is loaded with a database of every conceivable conversation that is less than an hour in length.  Then when taking the Turing Test, it looks up a conversation that matches up to the current sentence, and speaks the next sentence in that conversation.  He says that this machine is clearly not intelligent, and therefore intelligent behavior is not enough.  He does allow that computers could be intelligent, but they would have to be doing something better than this, such as learning or adapting.  Another student in the group brought up a great point that the Turing Test is fine if you say that it has to be a feasible machine that passes for a human.  Both this counterexample and the Chinese room are not feasible agents (the number of hour long conversations is much greater than the number of particles in the universe).  Any feasible agent (reasonable memory and computation power) that passes the Turing Test must be doing something intelligent to be acting that way with limited resources.  This is an interesting definition that lets the Turing Test stand and does put a restriction on the internal processing to be ‘feasible’, which any actually realized agent would be.

So where do I stand?  I’m not sure.  Intelligence may be defined on some scale by behavior.  More complex or more efficient behaviors come from more intelligent beings.  I’m not sure that a definition with a restriction on the internal processing of a being will work.  Intuitively I don’t think an agent that is simply looking up a conversation in its database like above is intelligent.  An agent that is learning or adapting seems to me to be more intelligent.  But depending on what level of abstraction you look at, even we aren’t doing anything that exciting.  Sure, you say that we’re understanding what is said to us, thinking of a response, using our memories, and responding.  Which sounds intelligent. But at its basest level, its just chemicals and ions flowing back and forth in our brain, following the inexorable laws of physics.  Which sounds very unintelligent.  The same thing applies in the case of AI.  You can write some cool learning algorithm that adapts and learns how to behave in some environment over time.  But of course how it learns was written by you and is pre-determined and the entire course of what it would do in that environment could probably be predicted if you knew all the variables.  So I don’t think any definition of intelligence that involves the internal processing going on could ever work, because every agent simply has very boring particles following the laws of physics at the core of their internal processing.

In summary, I think a definition of intelligence has to be about producing intelligent behavior and not about the internal processing that creates it.  The Turing Test seems pretty reasonable if you restrict it to feasible agents.  And I still think algorithms that let machines learn and adapt are more exciting that simply programming in a static solution to a computer (I prefer to think of things at the learning abstraction level than the level of particles following the laws of physics).

I just read Starship Troopers by Robert Heinlein. Some of the most interesting parts of the books are the descriptions of the main character’s classes in “History and Moral Philosophy.” This takes place in the future and looks back at the “failures” of our society and compares them with their solutions in the future. Some of the most interesting parts are about morality, the survival instinct, and how it relates to democracy.

The teacher in the book, Mr. Dubois, says “Man has no moral instinct. He is not born with moral sense. … We acquire moral sense, when we do, through training, experience, and hard sweat of the mind.” This is an interesting concept. Certainly when you look at animals you don’t think they are born with a moral sense. What’s more interesting is where he says our moral sense comes from. “What is ‘moral sense’? It is an elaboration of the instinct to survive. The instinct to survive is human nature itself, and every aspect of our personalities derives from it.” Where the moral sense comes in, is whose survival is imperative to you: “survival can have stronger imperatives than that of your own personal survival. Survival of your family, for example. Of your children, when you have them. Of your nation, if you struggle that high up the scale.” He claims that their theory can solve any moral problem, on any level: “Self-interest, love of family, duty to country, responsibility to the human race.”

This discussion of morality gets really interesting when he ties it in with their political system. In their system, you must serve your country (in some capacity: military, science, research, engineering, etc) before you are allowed to vote or run for office. But this service is not required, moreover it is done on a volunteer basis and discouraged so that only those who are truly committed accomplish it. Mr. Dubois explains that “Under our system every voter and officeholder is a man who has demonstrated through voluntary and difficult service that he places the welfare of the group ahead of personal advantage. And that is the one practical advantage. He may fail in wisdom, he may lapse in civic virtue. But his average performance is enormously better than any other class of rulers in history.”

I’m not advocating this system of government, but this argument makes a lot of sense to me. I’ve argued in previous blog posts here that one of the biggest problems with our government is that people are too concerned with themselves than the best interests of the country. Politicians are more concerned with raising enough money to keep their jobs than serving the country well. Many voters are more concerned with how the policies affect them than what it means for the country or for future generations. Restricting the decision making to only those who actually put the best interest of the country ahead of their personal interests would make the system more successful. I’m not quite sure how to do that. Even when we have candidates who put the country ahead of themselves, they don’t necessarily get elected because there are enough voters who don’t do so. Certainly some interesting questions to think about.

Here’s a quote that sums up how I wish the government (and its voters) operated: “In every deliberation, we must consider the impact of our decisions on the next seven generations.” — The Iroquois Confederacy

The editorial board of toddhester.net (members: me) has decided to endorse Barack Obama for Presidency of the United States. There are a good number of reasons for this as I will explain below, including his stance on the issues, his experience, his vision, and his electability.

Issues

In the democratic field, there are actually three very good candidates who are very similar on the issues. They want to bring the troops home from Iraq, they support lowering taxes on the poor and perhaps raising them on the rich, they want to all Americans access to health care. So they’re all very good on the issues, and I don’t think Obama, Hillary Clinton, or John Edwards really separate themselves here.

Fixing the System

The governmental system in America is broken, because instead of our politicians representing the interests of the citizens of this country, they represent the interests of the corporations and lobbyists that donated to them. Both Edwards and Obama have harped on this issue and talked about the importance of turning this around. Obama has repeatedly said he has not taken money from PAC’s, lobbyists, and special interests.

Experience

Hillary Clinton keeps talking about her experience as the reason she should be elected over Obama, but personally I prefer Obama’s experience to hers. She’s been a Senator 8 years to his 4 years, is that a very big difference? Hillary says she’s the candidate who can make change and will be ready on day one. Once you get into office, any candidate is going to surround themselves with smart people (and they’ll have the backing of their party) to get things done. Experience isn’t the question there. The question is, “Who will get the right things done, the important things done?” On this point, I have more trust in Obama. He has a father from Kenya and a mother from Kansas. He went to elementary school in Indonesia, he’s gone to Columbia and Harvard law. He’s worked on the streets of Chicago organizing and helping people. I think this broad experience gives him a better perspective on what’s important to this country that Hillary’s experience as first lady and US Senator.

Vision

Obama’s vision for this country is great. Whether he can bring it about or how he could do so is another question, but I don’t think you can argue with his vision of hope for this country and uniting us together again (although Hillary did claim it was just “false hope”). It’s important that we have a leader who actually wants to unite us together rather than just rally their base of support and piss off half of the country. It’s important that we have a leader who campaigns on the politics of hope rather than the politics of fear. You also get the idea from listening to Obama that he actually has a vision of what needs to be done in this country, while Hillary seems to just have a vision of whatever the polls say she should do on an issue.

Freshness

This goes along with the experience thing, but Obama brings a freshness to the political scene. Instead of the usual waffling of our candidates, whose views on the issues seem to be simply whatever is most popular in the country, Obama actually has his own views and convictions that he stands by. He was against the Iraq war from the start, while Hillary was for it and has since changed but refuses to admit her mistake and apologize for her original vote. We need someone like Obama to bring a fresh perspective and change the political system from being under the control of lobbyists and fear to the control of its citizens and hope.

Electability

In the case of selecting a democratic candidate that can win in the general election, I think Obama is it. Hillary would have a tough time in the election. Do we want 24+ years of rule by just Clintons and Bushes? She inspires the democratic base but is a polarizing figure for Replublicans. Edwards would be a viable candidate and I think would be pretty successful in a general election. But Obama’s vision and unifying message of hope would give him a shot at winning a landslide election over the Republican candidate.

Summary

In summary, I’m endorsing Obama because of his experience and vision for this country. His experiences on the streets of Chicago and in Indonesia give him a fresh perspective that this country needs. He has a message of hope and unity, instead of the recent politics of dividing the country into red and blue states. He has the ability to overcome the problems in this country and lead us back towards success.

I just read a very interesting interview with David Deutsch about the multiverse. Deutsch is a physicist who studies quantum mechanics. One of the craziest (but best proven) laws of quantum physics is the way photons and electrons behave both as a particle and a wave at once. In the famous experiment with light going through two slits, photons interfere with each other as if a wave and create an interference pattern. They do this even when only a single photon is sent through at a time and even if a detector is setup to see which slit each photon went through. Somehow even single photons are interfering with something. Deutsch’s explanation is that the photons are interfering with other photons in other universes (the multiverse). He then suggests that since we are made up of small particles like this, the same thing must happen to us as well. Therefore there are many parallel universes where we all exist.

Deutsch’s explanation of the light experiment is intuitively appealing to me. The traditional explanation of this sort of thing in quantum physics is that the particles exist as a probability wave which collapses to single point (or particle) when you view it. But the idea of particles as probability waves and our viewing affecting it is very awkward. The idea that the particle is interfering with infinite numbers of particles in other universes makes intuitive sense to me. And the extrapolation that even people are existing in multiple parallel universes is an interesting one.

In our reading group this week, we read John Searle’s classic paper “Minds, Brains, and Programs.” In the paper, he makes the claim that digital computers doing symbol manipulation cannot have intelligence. His motivating example is what he calls the Chinese Room Experiment. Basically, a man is inside a room. He is given a set of instructions to follow when he receives papers full of Chinese symbols. By following the instructions, he creates a second set of symbols which he returns. Although he does not personally understand Chinese, to an observer outside the room, they have just received fluent answers to questions in Chinese. Searle claims that this shows that intelligence cannot be created in a digital computer (the man) with a program (the instructions) because in this example the man clearly does not understand Chinese. I would argue that the room as a whole understands Chinese, as its the whole system that understands it (you wouldn’t expect a computer to be intelligent without its program). He argues that the system as a whole cannot have intelligence, and that some subsystem must have it. But the same systems rule applies to the brain, the brain as a whole has intelligence, but you can’t ascribe the intelligence to any subsystem of the brain such as a neuron or brain region.

The other main thing that bothers me about Searle’s essay is that he claims that human intelligence can never be replicated on a digital computer because a computer does not have the same “causal properties” as the brain. He claims that our intentionality is somehow created by these “causal properties” inherent to the brain that cannot be replicated in a computer. He makes no claim as to what they are or why they can not be replicated. I find it highly unlikely that our intentionality is due to some specific physical feature of the brain as opposed to an emergent property of the coalition of neurons in our brain. It seems like Searle is searching for some little homonculi in our brain that is directing things, and that we can’t recreate that homonculi in a computer. But there is no little man inside our brains.

One interesting point that Searle brings up is the separation of mind and brain. The separation of mind and brain may not be the same as the separation of a program and a computer. While a program can be run on any number of equivalent computers, the mind may be dependent on specific properties of the brain, or may be integrated in the brain rather than being some program that can be applied on top of the brain. I can agree that there are probably some aspects of the brain that are essential to mind, although I don’t see why we won’t be able to simulate those somehow in a computer.

In this talk, Seth Lloyd talks about the universe as a giant computer and the implications of that notion.  As I’ve described before, the universe is a giant computer because all of the atoms and molecules in the world represent information through their various qualities such as spin, etc.  Every interaction between atoms or molecules is, in fact, a computation.  Since the universe is infinite, this giant computer will compute everything possibly computable.  Since a computer can simulate any other computer, this includes computing more computers.  Namely, us.  As the universe computes all possible computations, some of this create increasing complexity, eventually leading to bacteria, animals, humans, and the computers we have today.

I find this idea pretty interesting.  In essence, the universe is a giant computer simulating us (who are also computers).  You hear about this philosophical “Brain in the Vat” question where we may just be brains getting simulated inputs and outputs from somewhere (the Matrix).  This takes it to a whole new level, essentially our whole existence in the universe is inside a giant computer that is computing everything.

Here’s an interesting article by Freeman Dyson on “Our Biotech Future.”  Basically he predicts that we will soon have personal biotechnology devices and all be able to be genetic engineers.  He suggests that this will create solutions to many problems and also perhaps help eliminate poverty.  One aspect that I found particularly interesting was that with this genetic engineering, there will be more competition between genes of various species.  So perhaps this new era of personal biotechnology would lead to faster evolution?  Although instead of being guided by Darwinian evolution, gene selection would be guided by lots of genetic engineers.  It certainly could result in some interesting (or dangerous) things.

There was a good article in the New York Times today on the effect dreaming has on learning and memory.  The fact that dreaming and sleep are good for learning and memory is commonly known I think.  Their description of how dreaming can help you make connections between memories is pretty cool though.  Your dreams could be your brain re-organizing your memories and what you’re learned and trying to find the connections between them.  Leading to inspiration apparently!  Now I have a good excuse for why I want to sleep 9-10 hours a night.

Here’s a ridiculous story predicting that we’ll be marrying robots by 2050.  Not only do they predict that, but they predict that Massachusetts will be the first state to legalize it.  I certainly see the sex robots coming very soon - the sex industry always takes advantage of new technology before anyone else.  But marriage with robots?  I suppose if robots are actually intelligent by 2050 and seem like equals to humans then maybe its possible.  But if not, then its like asking if people will be marrying their cars or computers.  A little absurd, I think.

A new study has shown that exercise makes you smarter by promoting neurogenesis in the brain.  In short, exercising helps create new neurons in the brain, which then improves your cognitive abilities.  Exactly why I bike to school everyday