Celtic Minstrel said:
About Wedge's comment that computers are bound by their programming... that's true of normal computers, yes. But what if a computer is able to alter its own programming?
This is really the key point. The classic picture of robots can't evolve. That's a major reason why they cannot display human-like behaviour. And by evolve, I mean the evolution of the computer's "brain" over time – its body it really irrelevant to this. It's "brain" is essentially its programming.
Hmmm, you might actually be right about that. I'm still a bit skeptical,though, because even if a robot's programming changes, the method with which the programming is
interpreted does not change. The programming of a robot is not the most fundamental part of it, the processor and RAM is. You could think of the processor and RAM as the actual program, and the program as a data file that is being interpreted by the processor, which is basically no different from a "traditional" computer (in which the program can't rewrite itself).
Ok, I'm sorry but I just can't bring myself to drop the free-will debate. SP/andwhy, feel free to move this next part into a new thread if you think it's too off-topic.
I read that blog you mentioned, andwhy, and there was some interesting stuff there.
miller said:
Too often, people only care about the question of whether free will exists, when they should care about what "free will" really means. And what do we really mean by free will anyway? Does that mean that we're free from outside influences? Does it mean that we are morally culpable for our own actions? Does it mean that our actions are unpredictable? Is it necessarily a supernatural force?
miller said:
"Unpredictable <=> morally responsible" just seems like a non sequitur to me, but hey, that's a problem for philosophy, not for physics.
These are good points. I should have mentioned earlier, that when I say "free-will" I'm talking about both unpredictability and moral responsibility. I don't believe that unpredictability implies moral responsibility, or vice-versa; it is possible to have one without the other. I suppose I would define free-will as the combination of unpredictability and moral responsibility.
miller said:
Bonus question: what's the difference between free will and its illusion?
That, I have an answer to. In order to have true free-will as opposed to the illusion thereof, you need true unpredictability and moral responsibility as opposed to the illusions thereof.
The difference between true moral responsibility and the illusion thereof is pretty obvious; do you do what's right because you genuinely care about other people, or just because you were taught to or just because there's some reward in it for you?
The difference between true unpredictability and the illusion thereof is not so obvious.
miller said:
In principle, classical mechanics are completely deterministic, but in practice they are not. If you've got a single particle, you can easily predict its motion, but if you have more, it's not so simple. If you have N particles, you have to keep track of 3N numbers to specify their coordinates, and 3N more to specify their momentum. Once you have at least three particles, the gravitational equations already become impossible to solve without approximations. In any typical system on the human scale, we'll have on the order of 10^22 particles. Because it is so vastly impractical to keep track of so much information, we instead use statistical descriptions of such large systems. Temperature is one example; it describes a probability distribution of energies for each particle. And that's why determinism does not imply predictability.
Well, that's not necessarily correct, depending on how you define "predictability". It is definitely possible to have a deterministic system which gives an extremely convincing illusion of unpredictability. As Miller pointed out, the more particles you add to a system, the more difficult it becomes to predict what will happen in the system. Once you get up to a "normal" sized system with about 10^22 particles, it is so insanely difficult to predict
exactly what will happen, that no human or computer could ever hope to do so. Therefore, we use those "statistical descriptions" like temperature, that Miller mentioned.
Now, suppose there exists some sort of omniscient, infinitely fast supercomputer that is capable of knowing the exact location, velocity, mass, and electric charge of every particle in the universe, and then calculating the exact location and velocity of every particle in the universe during every instant from the present time to infinitely in the future, all in a single instant.
In the deterministic universe described by classical, non-quantum physics, this supercomputer would always be able to unerringly, instantaneously predict the future of any system, regardless of whether there were 1, 2, 3, 10, 10^22, or 10^23049873478 particles in the system, so therefore the system is not
truly unpredictable, it just gives an extremely good illusion of it.
A system that is truly unpredictable would be impossible for anyone or anything, including this theoretical supercomputer, to predict with 100% accuracy.
I'd say more, but this post already probably makes the top 5 longest posts ever written on these forums, so I'll restrain myself xD.