Is Langton's Ant deterministic? Does Langton's Ant have free will?

[warpus]

More seriously, are you arguing that free will is dependent on quantum uncertainty? Are you suggesting that I must act differently in identical circumstances to have free will? Must I act "unpredictably" to have free will? If this is necessary, is it not then predictable? Are humans unpredictable?

My only point thus far is that if you are able to predict what I am going to do at any point in the future.. perfectly.. then it follows that I do not have free will.

I am not saying that you must act differently in similar situations to have free will.. I am saying that you must have a choice to act differently.

The ant obviously has no choice, since 2 simulations side by side always yield the same results, no matter what. The ant is obviously not making decisions of the 'free will' kind. It is simply following a set of rules. It is deterministic, like a grandfather clock. Do grandfather clocks have free will, or are they simply following a predetermined set of rules?

 

[Erik Mesoy]

I can predict that a grandfather clock will stick its pendulum to the left after an even number of seconds and to the right after an odd number of seconds... my point, which I'm apparently failing to get across, is that you can't really "predict" the Ant except by letting it happen, which isn't proper prediction, like my copied universe above. It's not "prediction" to let history happen and then go back in time with the equivalent of a time machine to an earlier point in time and then claim that you know what's going to happen.

Okay, the modified Ant:

The new and improved ant moves according to the rules below:

* Whenever quantum happens, do quantum.
* At a black square, turn 90° right, flip the color of the square, move forward one unit
* At a white square, turn 90° left, flip the color of the square, move forward one unit

Is it NOW nondeterministic? I haven't really added this rule, imo, just spelled it out. Previously, quantum effects could suddenly have skipped the ant nineteen spaces to the left through quantum tunneling or various quantum effects, and at the same time, quantum-medded with our brains to treat this as natural.

 

[punkbass2000]

I don't really have anything to add, but great thread.

 

[LucyDuke]

Chaos, baby.

 

[Pontiuth Pilate]

Here is where you went wrong

and has free will in that we cannot predict its behavior

There is a difference between a behavior being predictable and capable of being predicted.

Langton's Ant is predictable. We know exactly what it will do on any given square. You gave us the rules for predicting its behavior in two sentences.

You are arguing that the behavior of Langton's Ant cannot be predicted. Presumably because if you gave me a map of random squares the size of a chessboard I could not predict where it would end up in 50 moves. A computer could, though, in nanoseconds.

You would then expand the argument to say that there is a board size, or a particular arrangement of squares, such that any computer we have today could not "solve" the problem in a lifetime. In other words the behavior cannot be predicted.

But this does not show that the ant has free will. Free will by definition is behavior that cannot be logically resolved, 100% of the time, into complete theoretical predictability. The current state of the art in computers is not what's relevant here

A tangential example. I flip a coin. For simplicity's sake let's say I flip it in a vacuum. You cannot predict whether it will land heads or tails. But the coin flip is perfectly predictable. We could get 99% accuracy simply by simplifying the coin to a disk of uniform mass density and by knowing the angular velocity, the initial vertical velocity and the distance above the floor, and then applying physics equations.

A computer can already do this fast enough to give you an answer before the coin hits the floor. Thus making your expected value on any coin toss bet vs. a computer a loss of 99 cents on the dollar. Not a good bet.

We could get enough accuracy for all but 1 in ten trillion tosses by knowing the velocity and rotational and vibrational states of every atom in the coin. If we can get a complete observation of the quantum-mechanical states of every subatomic particle in the coin, there is no scientifically known reason why we would not be able to predict the outcome of the coin toss exactly one hundred percent of the time. You posit that knowing all quantum-mechanical states is impossible. I counterposit a being that exists outside of the universe and its physical constraints, e.g. God.

Arguing that the coin toss is a random event because we cannot predict its behavior is wrong. A coin toss is a deterministic event whose outcome we do not have the calculatory power to resolve.

Same with the ant.

Therefore Langton's Ant is actually a nice way to illustrate that if God exists, humans have no free will.

 

[Perfection]

What the hell is free will anyways?

I completely fail to understand the concept.

 

[plarq]

Chaos, baby.

Ten Char

 

[Mise]

If I were superpotent (not quite omnipotent, to avoid certain logical contradictions, nor omniscient), I could "copy" the universe, "freeze" the original in time relative to me, and watch the copy for a while. Once I unfroze the original, I would know what would happen there, since I've "already seen it happen". Do the inhabitants of the "original" universe then lose their free will and regain it once they reach the point at which I stopped running the copy?

If the universe were deterministic, one could do that. However, this does not mean that one does not have free will. "Free Will" sets what actions you are going to take -- it determines what the superpotent being finds when he runs the copy. But the superpotent being can never determine what your free will is, only what actions result. We know what the ant's "free will" is. Whereas we can decide whether we turn left or right at a black square, the ant can't; the ant necessarily turns left at a black square and necessarily turns right at a white square*. I'm sure you'll point to numerous examples of things that we can't perceive (what a 4D object would "look" like, comes to mind). But since you posited that the ant had as much, if not more, free will than we do, I think that this argument doth suffice.

Really, you are arguing against determinism, as opposed to Free Will.

*- the distinction between what is necessarily true and what is actually true is important.

 

[Pontiuth Pilate]

"Free Will" sets what actions you are going to take -- it determines what the superpotent being finds when he runs the copy. But the superpotent being can never determine what your free will is, only what actions result.

So God watches the tape and sees you will turn left. Now let's rewind and press play. Your move. Is there any way you can turn right? To use your language, do you NECESSARILY turn left? Are you making a decision at all or is there just an illusion of a decision? Are you in control of your own actions? If you aren't, who is?

I completely fail to understand the concept.

It's not a concept at all, it's a psychological defense mechanism. :\

 

[mdwh]

Being deterministic and predictable are different things - they are only related in that a non-deterministic process must also be an unpredictable one (and hence, a predictable event must be deterministic). The reverse implication does not always hold (deterministic events can be unpredictiable, as in this case).

I see that unpredictability is a necessary requirement for free will, though due to the above relation, it is more specific to say that non-determinism is a necessity for free will. So no, Langton's Ant doesn't count.

Neither of these are a sufficiency - we don't know what is sufficient for free will.

 

[mdwh]

Of course you could predict its behaviour.

It would be simple to write a computer program that would be able to forsee any of the ant's move in the future.

Thus it does not have free will.

You're talking about being deterministic here.

Although at first it seems that any deterministic event should be predictable, predictability is to do with how the outcome changes based on a small change in the inputs. So given that usually we can only measure things with finite accuracy, if a small error in the inputs means our results end up completely wrong, we call it "unpredictable". The classic example is weather - even if this is an entirely deterministic process, it's very hard to predict.

 

[Smidlee]

Therefore Langton's Ant is actually a nice way to illustrate that if God exists, humans have no free will.

( So according to your vote God exists. )

Not necessary since God could gave humans some of his abilities and powers. This is what I believe it means God created man in His own image as He gave us great power to create and destroy.
I have seen no one here in this forum speaks as if they didin't have a free will.

 

[Erik Mesoy]

Really, you are arguing against determinism, as opposed to Free Will.

No, what I'm really arguing against is the supposed dichotomy between them. As to the concepts themselves, I think they're somewhere between "poorly defined" and "rubbish".

@Pontiuth: Care to comment on the second post of the Ant's rules? Essentially, "if affected by quantum, behave according to effect of quantum".

More when I have time!

 

[Mise]

No, what I'm really arguing against is the supposed dichotomy between them.

Err, believe it or not, that's what I meant... "determinism, as opposed to free will", as in "determinism, in opposition to free will". Sorry, I knew that wasn't cleared the minute I posted it.

I don't believe that there is a dichotomy between them at all. Nor do I believe that the ant has free will.

 

[Mise]

So God watches the tape and sees you will turn left. Now let's rewind and press play. Your move. Is there any way you can turn right? To use your language, do you NECESSARILY turn left? Are you making a decision at all or is there just an illusion of a decision? Are you in control of your own actions? If you aren't, who is?

No, I don't necessarily turn left, I actually turn left. That I turn left is contingent on my free will. "God" knows what choice I'm going to make - that doesn't mean I don't have a choice to begin with.

 

[Bozo Erectus]

Is it permitted to turn the thread into a musical for just a second?

Is Langton's Ant deterministic? Does Langton's Ant have free will?

Just what makes that little old ant, think he can move a rubber tree plant? Everyone knows an ANT, CANT, move a rubber tree plant. But he's got FREE WILL! Hes got FREE WILL! He's got high apple pie in the SKY free will.

 

[punkbass2000]

 

[nihilistic]

Langton's Ant, however, is arguably less predictable. You cannot predict what it will do except by letting it run and then looking at it afterwards. If given a huge board with random distributions of black and white squares, the ant will move according to a very clear set of rules - but you can't really predict what it will do. You can work out its moves, but this is like reading a history book and declaring that the people described there don't have free will because we know what they did, since all you've done is to let the ant move on another board. We cannot, as with mathematics, simplify the calculations and "predict" in advance. We can add 2¹²°° + 2¹²°° and get 2¹²°¹ in less time than 2¹²°° planck times (ca 8*10³¹° seconds). We cannot skip Langton's ant ahead in the same way without losing precision, while the previous calculation is arbitrarily precise. (A planck time is the shortest known time in which something can happen.)

That is not "unpredictable". Since all the ant movements are deterministic, it is by definition predictable. Mathematics (when it comes to results) disregards all that run-time analysis stuff. It is not at all like reading a history book because a history book goes on and on with synthetic facts that cannot be predicted from past synthetic facts, while the synthetic facts of Langston's Ant includes only:

Langton's ant is a two-dimensional Turing machine with a very simple set of rules, invented by Chris Langton.

Squares on a plane are colored variously either black or white. We arbitrarily identify one square as the "ant". The ant can travel in any of the four cardinal directions at each step it takes. The ant moves according to the rules below:

* At a black square, turn 90° right, flip the color of the square, move forward one unit
* At a white square, turn 90° left, flip the color of the square, move forward one unit

With these rules you can predict every position in decidable time, so it is in no way "unpredictable. There are no unknown variables. Your second point of

"You cannot predict what it will do except by letting it run and then looking at it afterwards."

is also incorrect. The correct statement would be "a way of predicting it without running the program has not been found yet". To say what you have said, you'd at least need to prove that the problem is NP-hard.

 

[Erik Mesoy]

The drive-by link of the day is the No Cloning theorem, which suggests quantum free will.

Nice catch, nihilistic. Is there a proof of whether there can exist an automaton which is at least NP-hard?

 

[warpus]

I can predict that a grandfather clock will stick its pendulum to the left after an even number of seconds and to the right after an odd number of seconds... my point, which I'm apparently failing to get across, is that you can't really "predict" the Ant except by letting it happen, which isn't proper prediction, like my copied universe above. It's not "prediction" to let history happen and then go back in time with the equivalent of a time machine to an earlier point in time and then claim that you know what's going to happen.

You're attempting to make a distinction where one does not exist. You're asking if there's a way to predict, independently of the ant (which is off somewhere walking around), how the ant is going to move and where it's going to end up. Well, there sure is.. you have all the rules of the ant's movement recorded.. All you do is write a computer program to run through the rules and return the answer.

Just because the ant's movements are deterministic doesn't prevent you from essentially 'building a 2nd ant' and using the clone to see what the original is going to do.

The fact that the 2 ants do exactly the same things, no matter what, is a clear indication that neither ant has free will. If one did, the paths the two ants took would be different.

Okay, the modified Ant:

Is it NOW nondeterministic? I haven't really added this rule, imo, just spelled it out. Previously, quantum effects could suddenly have skipped the ant nineteen spaces to the left through quantum tunneling or various quantum effects, and at the same time, quantum-medded with our brains to treat this as natural.

No, it would be nondeterministic if you introduced a step dependent on some quantum process.. So, say, if a radioactive isotope of some sort decays at a certain time, then you move right. if not, move left. That would be nondeterministic. The way you have described quantum tunneling above doesn't really make sense - it is independent of the rules.

You're talking about being deterministic here.

Although at first it seems that any deterministic event should be predictable, predictability is to do with how the outcome changes based on a small change in the inputs. So given that usually we can only measure things with finite accuracy, if a small error in the inputs means our results end up completely wrong, we call it "unpredictable". The classic example is weather - even if this is an entirely deterministic process, it's very hard to predict.

Right. and in our case we have full control over the inputs as well as perfect data on the state of the experiment.. thus making the whole thing 100% predictable.

I have seen no one here in this forum speaks as if they didin't have a free will.

That is not a very good argument for free will.