The Computational Universe

My response to Brooks’ views is that I am not fully convinced that we are machines.  He is correct in saying that we still do not have a working definition of consciousness.  That is because we have not yet been able to fully grasp scientifically how our brains work, how they produce minds that think, feel and (especially) have consciousness – science has not yet been able to reduce our minds and consciousness to the workings and mechanisms of physical particles.  Although Brooks poses some valid criticisms to Searle, Chalmers and Penrose, and even if their arguments and predictions of “new stuff” that is still to be discovered, these three philosophers are at least correct in pointing to the fact that we have not yet figured out how the brain leads to (or causes) a human mind.

I do find Brooks convincing when he argues against the attempt to create centralized systems that organize perception and try to fit it into comprehensive mental maps.  Brooks does persuade me when he claims that the most fruitful direction that AI can take right now is to focus instead on the robot’s or computer’s interaction with the world outside of it, in a more organic and decentralized manner.

Meanwhile, even though Searle might be a little too radical in his argument, there is some nerve that he touches in his article that resonates with things I have been thinking about throughout this class.  One of the issues is related to simulation.  When AI researchers work on computers and robots with the aim of having them pass the Turing Test, of producing artificial intelligence, and in the more ambitious cases of producing consciousness – the way in which they work and their goal is to simulate human intelligence.  The simple fact of simulation raises (for me) a huge doubt as to whether such machines will EVER have real consciousness.  Isn’t simulation by definition supposed to be just that – to come as close to while never reaching the real thing?  Furthermore, and maybe more importantly, if scientists still have not figured it out what it is exactly in the brain that makes us humans conscious, then how can we be so sure that we could ever produce consciousness in anything else?

Even if Brooks is correct in pointing out that once we start building machines that interact with us in such a convincing manner that we start empathizing with them we will have to grant them a level of respect that comes closer to the respect we show other human beings, his view is NOT inconsistent with the fact that these machines, even if we greatly empathize with them, may not have consciousness in the way that we do.  Our own empathy is no measure for an objective fact – it cannot be the answer to the question of whether or not the machines have consciousness.  Brooks fiercely and constantly singles out the emotional desire to maintain our human specialness as the driving force behind arguments against the possibility of producing consciousness in machines.  In order to be consistent, then, he should also factor out any emotional ability we might have to empathize with very advanced robots as a measure for whether they have consciousness.  Neither our desire to be special nor our ability to empathize provide rigorous proof for the possibility of producing conscious machines.  Alas, I am afraid any and all objective proof to support wither side is still missing, so the question remains wide open for speculation.

I had planned to attend the Tim Berners Lee talk, but unfortunately did not make it. I will nonetheless write about the surprising things I did learn in lecture about the internet.

First of all I had no idea the World Wide Web even had just one inventor. It seems such an anonymous structural thing, with seemingly no “control center”, and necessary to just about anyone who wants to use the internet, that I assumed it must have been born from a collaboration or government project. Furthermore, the fact that he has demanded no royalties on a program that is used by billions of people daily points both to a sense of duty and to foresight; maybe if Berners Lee had requested royalties the WWW would not be as widely used and thus might have failed to become the powerful universal tool it is today, interconnecting and making available information from all corners of the globe.

It was extremely interesting also to learn about the inner workings of the net, with its shaky foundation, “best effort transmission” and decentralized control. The best effort transmission and shaky foundation parts made me understand why it is that the internet can sometimes be incredibly frustrating; errors in the download of pages and the sometimes excruciatingly slow gradual download happen because the data on a webpage gets broken down into little “packets” that can arrive out of order, possibly wait in a queue to get transmitted and even get dropped in the process. I found the “kindness of strangers” solution (where all sources have to halve their transmission rate when there is too much traffic) incredibly democratic and am impressed it works so well without enforcement.

A most fascinating fact that captivated me right away was the Turing Machines’ capacity to perform an incredible range of calculations – seemingly simple things having the ability to simulate the logic of any computer, no matter how powerful. Who would have thought an infinite, one-dimensional string of zeroes and ones and a finite series of extremely simple instructions could do all of that?

And then, to augment my fascination: the claim that the Turing machine can simulate every other computational model that can be physically built, which in turn means that ANY possible calculation can be performed by a Turing machine. The Turing-Church thesis grants so much power to that little machine, the silly binary string of ones and zeros, that the fact that it has not been disproved made me wonder if indeed we don’t live in a fully “computational universe”. Would future scientists, once the collection of mathematical formulas behind the natural laws has been discovered, be able to calculate most, or all past and future events? Does this confirm that we live in a fully deterministic universe, that in the near future we would be able to predict and fully explain just about everything?

Thankfully this was soon followed by the Halting Problem, which proves that there exist certain questions that cannot be decided by a Universal Turing machine (one of them being whether a Turing-Post program ever halts). I chose to interpret the insolvability of such questions as providing sufficient evidence to disprove (or at least prevent the confirmation of) the determinability of our universe. Relief: no matter how exciting and curious theses like the Turing-Church are, I like to be reassured of the unpredictability of my universe.

In reflecting about what I learned with my little robot Scribbler, I’d have to concur with Anu, who refers to the Scribbler as a technical thinker and discusses the detail and thoroughness required to program it.  The Scribbler labs, particularly the one in which we had to write our own pseudocode, provided to me first-hand evidence that a robot’s intelligence really is dependent on the programmer’s intelligence or thoughtfulness.  The directions that Scribbler requires to perform simple tasks correctly are very explicit and relatively detailed – not at all like the directions that even a small child requires.  One example of the limitations in Scribblers understanding of tasks: in order to program the robot to sense obstacles, it is necessary to insert a pause in between continuous move commands.  So I couldn’t simply tell my robot to, IF there were no obstacles (if it’s motor wasn’t stalled), move forward indefinitely or ELSE turn around and circumvent the obstacle.  The pause was necessary in order to make little Scribbler understand that, although I wished it to move forever in the absence of obstacles, it should also constantly be on the lookout for obstructions in its path.

The same goes for drawing that simple square.  It’s the programmer’s responsibility to figure out how many seconds the scribbler needs to spin 90 degrees, and how many seconds it need to move four inches.  And even then my little robot was extremely gawky: it would move back while spinning, leaving loops at the corners of the squares, shift a bit to one side by the third time it was doing the motions…

Such robotic imprecision can be quite frustrating.  But unlike Christine, I do not think that it derives from the fact that Scribbler does not have a “cognition box” or perception.  In his “Flesh and Machines” Brooks fully convinced me that eliminating a central planning and perception device (what he calls a cognition box) is quite an acceptable and smart solution to creating robots.  Responding to its environment without having some “mental map” or plan does seem to work better in allowing robots to perform physical tasks (at least for the moment).  Human beings themselves also use this responsive rather than analytical mode in everyday tasks such as walking to class, opening a door.  Poor little Scribbler’s imprecision, I suspect, derives much more from physical problems such as not-so-sensitive obstacle sensors, and most importantly imprecise motor calibration that makes it swerve to either side or move altering distances in the same time with the same force.

My name is Sofia Tsirakis, I’m from Brazil but my crazy sounding last name is Greek. I was also born in New York, which makes me have three citizenships, but really the tropical home of samba and good soccer is what I consider home.

I’m interested in this class in a more theoretical way – how is it really that computers work, the logic underlying the processes etc. So logic and math, that’s more my area rather than actual programming or video games. I’m shamelessly un-technological, into more old school philosophy, but very interested in learning some more in order to also have more material to look at the question of human intelligence, thought and consciousness. And it’s all really related these days with the advancements done in computing, so I’m excited for this class!

Pretty excited also for the robot art component of our lab – I am thinking of pursuing a certificate in visual arts, so maybe I’ll get some inspiration out of that experiment. So that’s one of my interests – art – which might explain the computer illiteracy. But then again more and more artists these days have been addressing the issue of computer technology related to art (photoshop, digital film and photography) so that’s another angle of interest.

In terms of philosophy, I’m utterly in love with Plato and into some German philosophy too. Taking a class on Heidegger who, countering Descartes’ “I think therefore I am” theorizes that the essential aspect of our being is how we go about everydayness, unaware mode. Maybe some basic knowledge of AI will be an interesting addition to that class.

Update 2:50pm on 2/12/2006: I use a Mac PowerBook.