We’ll see what I can get to today, but let’s start with this.
Did I ever do that? I was trying very hard not to. I recognised that it was very likely such errors could be made in ignorance, but I will admit that it crossed my mind he might be doing it on purpose.
The closest I can find to saying anything like that is this:
[QUOTE=ch4rl3s]
Starting by claiming it is in the system and now claiming you’ve only been using it as a convention, (as well as being untrue,) is truly, truly, bad form.
[/QUOTE]
I was simply making a statement of fact, without making any judgement as to whether anyone was bing dishonest. If you claim a symbol is a member of a set, then claim you were not claiming it was a member of the set, (only using it as a shorthand convention to describe another set of symbols that were members of the set,) that would be an untruth. Saying the statement is untrue. Not saying he didn’t convince himself he was only using it as a convention.
[QUOTE=Half Man Half Wit]
– everything he’s said so far, best as I can tell, can be understood as being perfectly well in line with common mathematical usage, and it requires some impressive contortions you seem all too willing to perform to read any sort of sly duplicity into it…
[/QUOTE]
Did you even look at what can actually be demonstrated from what we’ve said?
[QUOTE=Half Man Half Wit]
…and even if he sometimes was less than strict, terminologically, his points are reasonably clear, and valid…
[/QUOTE]
No! They aren’t!
Let’s look at what can be verifiably demonstrated!
Mathematicians believe that Presburger Arithmetic, and other similar systems, are complete. They believe that more powerful (and/or expressive) systems can be made complete, but not without making them inconsistent. Presburger Arithmetic can be formed by removing axioms from a more expressive arithmetic, (Peano Arithmetic.) Godel stated that you **could not complete **a formal system without making it inconsistent. These are all demonstratable facts. I’m going to add the ‘personal’ claim, (as if I’m the only one who would claim this,) that Godel meant that formal systems could be completed, (I’m not going to claim this as demonstratable.)
This is what Indistinguishable has claimed he was saying about completeness all along:
[QUOTE=Indistinguishable]
Removing axioms from an axiom system will only cause it to be able to prove less. So, what I was saying was, if you start with an incomplete axiom system, and remove axioms (while keeping the language of statements one is dealing with the same), then the system one ends up with will necessarily be incomplete as well [it can’t prove anything the starting system didn’t].
You make oblique reference to the completeness of “impoverished” systems such as Presburger Arithmetic and so forth. But this doesn’t contradict what I was saying. Sure, you can think of Presburger Arithmetic as Peano Arithmetic with all the axioms about multiplication ripped out… and if you think about it that way, then Presburger Arithmetic is incomplete
[/QUOTE]
He has also claimed that is the ‘mathematic’ definition of complete. Let’s assume that Presburger is incomplete because it says nothing about multiplication, (without ever explaining why multiplication is necessary,) then I can demonstrate that even if we take Peano, which includes muliplication, and add axioms to make it say everything possible about multiplication, it still can never be complete because it says nothing about an operator I’m about to invent. I’m going to call it Bazoongas. (when I told my room mate that, he said, “oh, you absolutely have to do that. Math needs more Bazoongas.”) I’m not yet going to describe it’s actions on the members of the set. You realize that addition was invented, that multiplication was invented, that we can always invent new operators; that we can always add new members to whatever set we start with; that we can always extend the logic we use… (you realize that propositional logic was invented; that it was extended by the invention of first order logic; which was extended by the invention of second order logic; there are more extensions and we can always create more.)
And do you realize from this that he’s claiming that nothing in math can ever be complete? But, but, but… (whimper…) how on earth am I going to reconcile that with the demonstratable fact that mathematicians believe many systems are complete or can be completed??? (how???) Do I dismiss what is demonstratable fact? Or do I dismiss Indistinguishable’s definition of what is ‘mathematic completeness?’ But Half Man Half Wit has claimed Indistinguishable is most often right about these things!!! Don’t I have to believe him? Whatever am I to do??? Well, why don’t you guess what I’m going to do?
Now. Let’s look at Godel’s claim that no sufficiently expressive formal system can be completed without becoming inconsistant. Indistinguishable claims it has no serious implications. I can see that, from what he believes ‘complete’ means. No formal system can ever be completed, so, you never have to be concerned with completeness causing inconsistency, so, of course, this would have no consequences. There would never be a reason to even state this. Apparently, Goedel was a fool. Or Indistinguishable is wrong about what is a mathematic definition. My claim was that Godel believed that formal systems could be completed. Whose claim makes more sense?
[QUOTE=Half Man Half Wit]
In fact, it seems your argument has reduced to mere semantical quibbles as opposed to a discussion of actual content, so perhaps it would be appropriate to get back to the origin of this whole argument, your assertion that
[/QUOTE]
[QUOTE=ch4rl3s]
the implications of Godel’s proof are that to have a theory that can explain every interaction in this universe, you have to start with a system that involves things outside the universe.
[/QUOTE]
Sigh. Do you realize how we got to this intricate math discussion?
I claimed the statement above; which is a proposition about how to derive a ‘theory of everything,’ (I meant everything in this universe, and without it becoming inconsistent. I hope that implication was clear.) And it started with a premise that Godel’s theorem had those implications.
With me so far? I have a proposition based on a premise, right? Certain people have **not accepted **my proposition because they **don’t believe **the premise! If I am to **establish the proposition **as valid to those people, I must first establish the premise!!!
Please, please, please, answer this question: Can I establish a proposition, (based on a premise,) without first getting people to accept the premise??? Can I? Please answer this one!
But you are asking me to stop trying to establish the premise, and get back to proving the proposition. That is truly, truly, truly bad form.
And also, please answer this question: Are you actually asking me to stop trying to establish the premise and get back to proving the proposition? Would you truly ask that?
[QUOTE=Half Man Half Wit]
which is a bit overreaching in stating the philosophical implications of Gödel’s result – it’s true that there are those that argue that the incompleteness theorem makes a theory of everything impossible, most prominently Stephen Hawking, …
[/QUOTE]
I can explain a little more about that claim in a moment. And I purposely decided not to use this example of a physicist who believed these implications, as prominent as he is, because I didn’t think a single example would hold any weight with this particular audience. Do you personally find the single example of Indistinguishable more believable than the single example of Stephen Hawking? Or did you accept my premise in the first place and were supporting Indistinguishable’s attack on it for some other reason? If you **accept the premise **I **can actually discuss the proposition **with you.
[QUOTE=Half Man Half Wit]
but even this doesn’t say anything about a need for ‘extra-universal’ explanations (it merely makes physics inexhaustible and ensures that there’ll always be a job for theoreticians), …
[/QUOTE]
Let me give an example, (which will try to address some of your other concerns about what we may actually need for a theory of everything, as well.)
Let’s start by assuming, (just for the sake of argument,) that the universe could be described by a completed formal system consisting of the natural numbers, a set of axioms, and addition and multiplication. Let’s further assume that this complete system falls under Godel’s theorem; it is inconsistant. To describe the universe, we need it to say everything true about the natural numbers under addition and multiplication with these axioms.
We could simply never complete it. It will be consistent, and only describe things in the universe, but it will never thouroughly describe the universe.
But, what if we could start with a consistent and incomplete system of natural numbers, with addition and most of the implications of multiplication, (we have these now,) and extend it with new numbers, say the rationals, and/or a new operator, which has the implications of multiplication that our incomplete system lacks. This new system may say everything we need it to say about the natural numbers, addition, and multiplication, but it won’t be complete itself, because it won’t say everything about our new numbers or our new operator, and it could still be made to retain consistency. But it will now assert some things about the new numbers and operator as true. But these things would not be things in the universe we know, and may never be observable. This would be a theory that starts with a model larger than our observable universe in order to encompass every true thing about our universe, while still being a consistent and incomplete system.
But is it realistic that a system encompassing only the universe would need to be complete? I think it probably is. I think a theory would have to explain all the particles in the universe, as well as describe space and time, and every possible way those particles interact with each other and how they effect spacetime around them. And that’s without proposing that it describe where, and in what state, every particle ever was for all time.
But, what if I’m wrong and it is just possible that our universe only needed some of the implications of multiplication? (going back to our simplistic model for illustrative purposes.) Well, we may just be able to eventually find a system that has just those and only those implications without being complete and remaining consistent. Or, it would still probably be easier to find a system with most of the implications of multiplication, and recognize that some of the true statements in this system describe things that are not in our universe. (i.e. a theory, like I stated before, that is larger than needed to make sure we encompass every true thing about our universe.)
oops. running out of time, gotta go.