Search All of the Math Forum:
Views expressed in these public forums are not endorsed by
Drexel University or The Math Forum.
|
|
|
|
Re: Formally Unknowability, or absolute Undecidability, of certainarithmeticformulas.
Posted:
Jan 27, 2013 6:41 PM
|
|
On 27/01/2013 1:02 PM, Frederick Williams wrote:
> Nam Nguyen wrote:
>>
>> On 27/01/2013 12:07 PM, Frederick Williams wrote:
>>> Nam Nguyen wrote:
>>>>
>>>> In some past threads we've talked about the formula cGC
>>>> which would stand for:
>>>>
>>>> "There are infinitely many counter examples of the Goldbach Conjecture".
>>>>
>>>> Whether or not one can really prove it, the formula has been at least
>>>> intuitively associated with a mathematical unknowability: it's
>>>> impossible to know its truth value (and that of its negation ~cGC) in
>>>> the natural numbers.
>>>
>>> No one thinks that but you.
>>
>> If I were you I wouldn't say that. Rupert for instance might not
>> dismiss the idea out right, iirc.
>>
>>> Its truth value might be discovered tomorrow.
>>
>> You misunderstand the issue there: unknowability and impossibility
>> to know does _NOT_ at all mean "might be discovered tomorrow".
>>
>> It's impossible to know of a solution of n*n = 2 in the naturals
>> means it's impossible to know of a solution of n*n = 2 in the naturals.
>> Period.
>>
>> It doesn't mean a solution of n*n = 2 in the naturals "might be
>> discovered tomorrow", as you seem to have believed for a long time,
>> in your way of understanding what unknowability or impossibility
>> to know would _technically mean_ .
>
> I am not talking about the words 'unknowability' and 'impossibility to
> know' the meanings of which I know. Nor am I talking about 'It's
> impossible to know of a solution of n*n = 2 in the naturals.' I'm
> talking about 'There are infinitely many counter examples of the
> Goldbach Conjecture'.
Ok. So you seem to be saying that (unlike the lone Nam Nguyen) everyone
should not think that it's impossible to know the truth value of cGC
since "its truth value might be discovered tomorrow", according to your
knowledge about mathematical logic.
But, A) what's the technical definition of "might be discovered
tomorrow"? "Tomorrow" relative to which side of the International
Date line? The Australia side? or the US side? And B) what happens
if before "tomorrow" has arrived, "today" somebody would discover
the truth value of cGC, rendering "might be discovered tomorrow"
_meaningless_ ?
I meant, what would "tomorrow", "today" have anything to to with
_mathematical logic_ ? And, would you have a concrete proof that its
truth value "might be discovered tomorrow"?
How do you know that it's _not_ impossible to know the truth value
of cGC?
All that aside, this thread ultimately is about an example of
non-canonical interpretation of the semantic of logical symbols
in general.
Would you be in the position to offer some evaluation, insight, on
such non-canonical interpretation?
--
----------------------------------------------------
There is no remainder in the mathematics of infinity.
NYOGEN SENZAKI
----------------------------------------------------
|
|
|
|
