It's interesting (to me) that chess is decidable in principle; that is, it is definitely the case that either

a) White can always win
b) Black can always win
c) If neither player makes a mistake, the result is always a tie.

In this sense, chess is no more interesting than tic tac toe... except that it may be impossible (given current physics theories) to actually search all the possible games to determine which of a,b,c is actually the case.

It's possible some final grandmaster will find an unbeatable opening and prove a or b; quantum computers might manage the brute force solution.

But does a question to which we will likely never know the answer actually have one?

Well, it might be closer than we think.

There are 'only' about 10^43 to 10^48 distinct positions in chess (a chess position can be totally described in 160 bits or less, and 2^160 =~ 10^48).

If you are interested in imperfect but unbeatable play (meaning it won't find a win/draw in the minimum number of moves), then an interesting prospect appears. A large part of the game tree is nonsense, filled with ridiculous positions and grotesque material mismatches. A good conjecture is that the total number of positions that need to be hashed is the square root of the total number of positions, or at most 10^24 positions. A standard chess program could solve the positions with grotesque material mismatches, and would need to reference the 10^24 or so other, non-ridiculous positions. It works out to be between about 10^13 Terabytes and 10^16 TB of memory. Er, that is still a lot :)

I note that the largest database today (French Telecom) is about 30 Terabytes....if a Moore's Law of memory holds up for a while, then we might see something like this in a few generations.

Esoteric? Every adolescent imagines such a thing.

It is a part of growing up to realize that the mind can imagine things that cannot be and stop fretting about it?

Or do you believe in the real existence of, say, Quetzalcoatl?

As far as Matrix-style illusions, Robin Hanson at George Mason University provides some fascinating arguments that we are almost certainly living in a simulation (the mind of God?). I can't say I've digested all his arguments, but they're worth considering.

Also, count me in as a Platonist.

For all we know, that is true.

For all we know, it isn't.

What we do know for sure, is that it is undecidable.

I think I'll file it under "WHOGAS*"

*Who Gives A S[darn]t.

Exactly. You get the same result (at least up to death) whether simple materialism explains everything or we're characters in a dream sequence of the Big Spook.

No point worrying about what you cannot affect.

Harry:

Well put, the adolescent learns that to live is to have faith in the unprovable, because all is unprovable.

Cool, the Guinnine Creed.

I didn't learn that.

"If that sounds a bit too esoteric to grasp..."

So you mean, like, we could all just be, like, figments of like, some super alien's imagination? Like, woah man, far out!

Heh heh.

Actually, to live involves inhale, exhale, repeat.

One other thing the adolescent learns is that granting one or two obvious things axiomatically makes everything else provable.

I'm not as much a platonist as I am a multi-dimensionalist: it is merely an assumption that an "abstract" "higher" world would necessarily be a "perfect" one.

See the "Flatland" series by various authors to show how higher dimensional beings and dimensions can, and cannot, interact with lower dimensional ones. One could postulate a nation-state of such beings following (or being forced to observe) some form of Starfleet's prime directive of non-interference (which, by the way, was never depicted as a total ban, but has developed nuanced loopholes and exceptions in the paper literature).

Harry's bleatings that there are no such higher dimensions that HE, harry, has observed, makes him sound like the pre-visitation square of the original book. How provincial.

Thus, it was with interest that I noted a recent Computer Science paper detailing a method for breaking out of a handheld's Java Machine sandbox. The point of the sandbox is to deliberately impose a set of known behaviors which analysis has shown cannot, in combination with an analyzed and conforming compiler, Virtual Machine, and security policy, be combined in any conceivable combination of operations to access memory that is not controlled by the program itself (I.e. the password database in another application in a different sandbox). In other words, the attempt of the Java virtual machine is to create a "closed" world, where any possible memory access cannot reach outside of the memory space expressly granted to the progam. The similarity of the closed VM memory universe to the physical universe, whose natural laws appear to be restricted to three dimensional interactions, is at least obvious to me, if not to harry: The inability to "see" a fourth spatial dimension is less due to the lack of one than the possiblity that each dimension is closed with respect to lower dimensions, but open to higher ones.

The trick for breaking out of the Java VM appears to be to allocate and initialize large blocks of memory, AND WAIT FOR A COSMIC RAY TO FLIP A BIT. the discussion is pretty involved, but the authors of the paper (http://www.cs.princeton.edu/~sudhakar/papers/memerr.pdf) actually wrote the program and succeeded in breaking out of the VM, simulating cosmic ray bit flips by heating a PDA to induce memory errors.

What's so intriguing about the feat is that, NORMALLY, such bit flips would cause most PDAs to either crash or abort the program: It's seen as a bug. A carefully crafted program, however, TURNS THE BUG INTO A FEATURE, and is able to leverage the incident into a security breakout about a third of the time.

The physical analog suggests a strategy of laying out a network of sensors to sense "unusual events", and use the information gathered to "somehow" leverage a foothold into the fourth dimension from the third.

Cynics would say, "Yeah, and right THERE in your plan, is where the miracle takes place to make it all work."

EXACTLY. The events the network would be looking for LITERALLY WOULD BE MIRACLES. Harry and the pure materialists would dismiss reports of such as "aberrations" or "fabrications", just as a PDA would crash or dismiss the program affected by a cosmic ray as an "errant" program. This puts new meaning to the saying "Be prepared".

Constructing a sensor array of sorts and waiting for a putatively rare event may be dismissed By harry and cohorts as silly and idealistic, but establishing the answer to the question of whether protons decay involved constructing a very specific sensor in a very specific location and waiting a LOOOOONG time. Similar to the search for proton decay, it would have taken only a few events to prove proton decay, but the lack of evidence could not be used as PROOF that proton decay didn't happen: The half life could be longer than estimated, or perhaps the sensor design is flawed in some way.

Finally, the religion that Harry apparently distains and opposes most coincidentally still promises a continuation of trans-dimensional events of the type Harry dismisses as impossible. That same religion, however, asserts that such events happen and are visible only to those who are prepared: those who believe. Is it a coincidence that everything Harry and the materialists say and do are precisely calculated to ensure that NOBODY BELIEVES?

Makes one question whether Harry and company are fellow inmates in this three dimensional asylum, or are collaborating with the keepers...

Ptah:

You weren't by any chance foaming at the mouth when you typed that, were you?

Look, you might be right.

I might be in the Matrix.
I might be a brain in a vat, being prodded by scientists to have fake sensory perceptions. One of those scientists might be Harry.
We might all be figments in God's imagination.
We might all be figments the imagination of a superbeing from another dimension.
Or two superbeings.
Or a million and twelve superbeings.

There are infinite other alternatives to the materialist view that "this is the universe, everything is real and this is all there is".

I can't disprove any of them.

The question is: so what?

Brit:

Or a God or gods could have Created everything or it could just be some blind natural process... All are equallt silly when you examine them. Though some are more elegant than others.

Yes, they might be 'equally silly'. We all have those 'naked lunch' moments....(what is 'matter'? And why?).

But some things are supported by physical evidence, and others are not.

The next question after "so what?", is: "so what reason do I have to believe it?"

Brit:

Physical evidence is indeed a good reason to give credence. No one here denies that. It is your(pl) dogmatic rejection of other kinds of evidence that comes between us.

Peter:

Agreed.

Count me as a non-Platonist.

There may be larger dimensions, and inaccessible realms, but that is not the same as saying that the abstractions of physical objects are in some way separate objects in and of themselves, and in some way more perfect than the objects that they describe. Perfection is a mental state within a brain, and not a property that can be attributed to an object. It is a subjective value - notice that the idea of the 'perfect' woman can be greatly affected by the liberal use of alcohol.

Peter/Brit:

You've both missed the point completely. There's no such thing as physical evidence--all we have (assuming there's a we) are mental perceptions.

Jeff:

You have faith that you breathe, etc.

Ptah's elaboration boils down to the psi-researcher's explanation of why, when you put controls on the experiment, the observed effects disappear -- the shyness effect.

The power chooses not to be observed by skeptics.

Well, that's ONE possibility.

Harry:

No, it's the Heisenberg principle writ large--what we observe we change.

OJ

No - mental perceptions MIGHT be all we have. You can't prove that there's no such thing as physical evidence.

So, so what?

First, convince me that y'all are sentient. Then we'll worry about whether we exist.

Brit:

So all is merely choices between faiths.

Bishop Berkley is always the best place to start on conundrums of this sort:

Three Dialogues Between Hylas and Philonous by George Berkley

And Godel's proof would seem to trench on this idea:

Godel's Proof by Ernest Nagel, James Roy Newman, Douglas R. Hofstadter, and Godel, Escher, Bach: An Eternal Golden Braid by Douglas R. Hofstadter

Once you have digested that material, try this:

Wolpert, David H. On the computational capabilities of physical systems part I: the impossibility of infallible computation, and On the computational capabilities of physical systems part II: relationship with conventional computer science

Robert is right to bring up Berkley. OJ is spouting pure Berkelian idealism.

Most people tend to be happy with Samuel Johnson's famous, if anti-intellectual, refutation.

But funnily enough, OJ's old pal David Stove (useless as he was on Darwinism) did a decent job of skewering the argument that because we perceive things, only our perceptions exist.

He called it The Worst Argument in the World (TM).

Equivalent to: we have eyes, therefore we can't see.

Brit:

Of course we're satisfied with Johnson, that's the point. He doesn't offer an argument to refute idealism--there is none--he pitches a fit.

Indeed, though I gave the Johnson link more for its amusement value.

Here are some more substantial arguments to consider:

1)Our old friend Ockham's Razor offers a refutation to Berkeley's idealism.

The simplest explanation for why I have these perceptions of things is that these things exist.

Berkeley's insistence that a busy God is constantly arranging these perceptions to make sure they're all consistent requires rather more of an effort to believe.

2) If you accept idealism, why not solipsism?

3) The reason Stove called it The Worst Argument in the World is because the logic of:

a) I have perceptions of things
b) therefore those things can't exist.

is flawed.

Brit:

Yes, those are all the jesuitical arguments that we substitute for reason:

We can conceive of God therefore He must exist. Every effect we see has a cause therefore there must be a First Cause. etc.

We all simply settle on Faith, because Reason fails its own test.

OJ:

I think you've got an argument in there, but you're struggling to formulate it.

In this thread you're oscillating between two different arguments.

The first, which is your usual one, is that "a belief in the true existence of the material world, and indeed in the existence of reason, is just another faith."

What this means is: "it is just as possible to doubt the material world, and indeed reason itself, as it is to doubt God, or that I'm not plugged into the Matrix etc."

That is undoubtedly true, but...."so what?"

The second argument is probably forced by the "so what?" question. This is your positive assertion above that "There's no such thing as physical evidence--all we have (assuming there's a we) are mental perceptions."

In other words, you positively assert that idealism is true. There is no such thing as the material world independent of perceptions, or at least, if there is an independent material world, we can never know it.

To which my question is: "That may be true. I can't disprove that. But I doubt it. So why should I believe it?"

Brit:

Isn't that the same argument? All we do have is our perceptions, or think we do--even that assumes that we exist and are not someone else's perception. All we can do is have faith that we do exist and our perceptions are mostly worthwhile. We start from a point of faith. Nothing, contrary to the claim of science, can ever be disproven.

You shouldn't believe it. No one truly believes. No one is truly rational. It is intolerable to the mind. Just believe. Kick the rock and move on.

OJ:

They're very different arguments, and require different responses.

One states, correctly, that it is possible that something may not be true.

The other asserts, less justifiably, that something is definitely NOT true.

It's equivalent to the difference between arguing that OJ Simpson might not have done it, and positively stating that he was innocent.

Brit:

No, it isn't.

It is true that we can have no rational proof of existence. Reason subverts itself anmd leaves only faith--or common sense if you feel better calling it that.

"It is true that we can have no rational proof of existence."

Agreed. And neither can you prove that there is NO such thing as objective reality. So...

"Reason subverts itself and leaves only faith--or common sense if you feel better calling it that."

What does that mean?

Does it mean that we all just assume that objective reality exists and get on with it? If that's what you mean by 'common sense', I agree.

So is that your argument against Darwinism?

No, it's the first argument, that as a choice of faith's it is aesthetically unappealing. The final argument is that it is not a science.