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Author Topic:   0.99999~ = 1 ?
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 115 of 237 (544192)
01-24-2010 4:53 PM
Reply to: Message 112 by Jon
01-24-2010 4:05 PM


Re: Totally right!
If I've erred (possible), then please rephrase it in the form of a proof which can point out my errors; i.e., show which aspects of the following are inaccurate summations of SG's argument, and please correct them:
I have done so.
P "All real numbers have properties X"
P ".9999| does not have properties X"
C ".9999| is = 1 and it is false that .9999| ≠ 1"
So far, you folk have just been calling me foolish and telling me my logic is faulty; no one has yet to show me why or where.
This is, of course, not true.

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 119 of 237 (544201)
01-24-2010 5:33 PM
Reply to: Message 110 by Jon
01-24-2010 3:53 PM


Re: Real Numbers and Real Ity1
So, does the 'real' in 'real numbers' have any relation to the 'real' in 'reality'?
I think the confusion has come from me assuming that it in some way does, but the more folk describe this concept mathematically, it appears that I was on the right track with my first post:
Jon writes:
Message 87
... a real number, which seems more a matter of definition than a matter of real-world fact.
Which seems in line with what (I think) Catholic Scientist and RAZD have mentioned earlier; namely, that the equality of 0.9999| and 1 is more of a result of the way in which you have defined your system; defining it differently gives us different 'equalities' of infinites to 1. In other words, you have not given a definition (as far as I can tell) of 'real number' that defines it concretely in terms of 'reality', but merely the one you've given defines it in terms of the 'established mathematical system'. (RAZD (Message 12) gave the lovely example of the equivalence of .8888| and 1 in a nonary system.)
Let us plug what you've introduced back into the proofsas I understand it(here, property Z is the properties you have listed that define 0.9999|too many to list separately, we variablize them):
P "All #s with property Z are REAL within MATHSYSTEM (i.e., ((R/Z)/M) (M=MATHSYSTEM)"
P "0.9999| has property Z"
P "(The REAL of 0.9999| is True) given MATHSYSTEM is True (i.e., ((R/0.9999|)/M))"
P "[proof of M=True]"
C "(R (the REAL of 0.9999|) is True... period"
Proof that .9999| is not DISTINCT (from 1):
P "It is false that 0.9999| is both REAL and DISTINCT (from 1) (~(RD))"
P "(R (the REAL of 0.9999|) is True... period"
C "0.9999| is not DISTINCT (from 1)"
In essence, there has been little done in regards the explanations given for why 0.9999| is REAL other than to introduce the variable, in form of caveat, MATHSYSTEM, the veracity of which (i.e., its conformity to reality, last premise in first proof) must now be shown to support the proof for 0.9999| being REAL and making the conclusion that it is not DISTINCT (from 1) unavoidable (within the world of reality, in which we all strive to live; if it is the case that the only place where such a proof has relevance is within the world of number manipulation (MATHSYSTEM), and the MATHSYSTEM is not necessarily related to the real world, then I've little interest in continuing to understand the equality of 0.9999| and 1, since it would appear little more than a novelty of an imperfect system which allows functions and manipulations that do not have reality as their basis). Of course, it may be that our conditions for DISTINCT (from 1) are also only definable given MATHSYSTEM (D/M)i.e., that all parts of the proof's conformity to reality hinge on the veracity of the MATHSYSTEM, the disproval of which bringing destruction to the proof, but for now it will be enough to focus on just the REAL of 0.9999|.
So, I look forward to your proof of M=true, or the admittance that the MATHSYSTEM is not necessarily related to reality.2
Jon
This is gibberish.
Let me try to explain the situation.
If we restricted ourselves to the rational numbers, then various perfectly nice and useful quantities such as pi and the square root of two would simply not exist in our number system.
Therefore, we construct a system, the real numbers, in which these and other such irrational quantities are numbers (indeed, so that every Cauchy sequence has a limit).
We then require some convenient form of representation whereby we can write the real numbers and perform arithmetical operations such as addition and multiplication on them. It is hardly convenient to work with Cauchy sequences for practical purposes.
One representation of the real numbers commonly used for this purpose is decimal notation. One of the things which we are allowed to do in decimal notation is to write that a sequence of digits after the decimal point recurs indefinitely. This allows our notation to express precisely all rational numbers, which is nice.
Since we are allowed to represent such infinite string of digits in our notation, we can write 0.9999~.
If we declare this to be not equal to 1, we involve ourselves in paradox, for then we could write 1 = 3/3 = 1/3 + 2/3 = 0.3333~ + 0.6666~ = 0.9999~ ≠ 1.
We could simply place a taboo on writing 0.9999~ (and any other expression ending in recurring nines), but in the first place, why should we? --- and in the second place, such expressions will arise naturally from our algorithms for addition, as when we add 0.3333~ and 0.6666~.

This message is a reply to:
 Message 110 by Jon, posted 01-24-2010 3:53 PM Jon has replied

Replies to this message:
 Message 120 by Jon, posted 01-24-2010 6:56 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 121 of 237 (544207)
01-24-2010 7:15 PM
Reply to: Message 120 by Jon
01-24-2010 6:56 PM


Re: Real Numbers and Real Ity
Excellent. So you have chosen to assert that there is a disconnect from MATHSYSTEM and reality, and without such a necessary link, you are free to claim MATHSYSTEM = True.
Actually, I have chosen not to recite gibberish of your own invention.
This is exactly what one would expect in a system which represents two identical real-world values (values from REALWORLDSYSTEM) with two different symbologies.
As, for example, the system of fractions, in which 1/2 = 2/4. I have noted that no-one gets their knickers in a twist over that.
(That is, one would expect there to be a necessary disconnectand not a necessary relationbetween any two systems if the same thing in one system had altering representations in the other, cf. Language.)
The difference is that any systematic way of mapping decimal representations to real numbers must necessarily identify 0.9999~ as 1, whereas there is no equivalent necessity that, for example, the sequence of letters l-a-r-g-e should map to the same concept as the sequence b-i-g.
In the case of 0.9999~ it is a matter of logical necessity. If we want our decimal notation and the associated algorithms to represent the structure of the real numbers, then 0.9999~ must be equal to 1. If it isn't, then our notation does not represent the real numbers.
In fact, it is this disconnect that is primarily at the heart of the necessity of the DISTINCTness criteria, which says that "for any numbers A and B with the following properties X, they are not formally DISTINCT in the REALWORLDSYSTEM, though being formally distinct in the MATHSYSTEM". This is necessary, because as you point out, without it, we could get ourselves into a paradoxical mess in which the MATHSYSTEM would start out representing the REALWORLDSYSTEM and then end up not doing so (which is fine if we do not wish the system to work, but we do wish it to, so it is far from fine).
1 = 3/3 = 1/3 + 2/3 = 0.3333| + 0.6666| = 0.9999| ≠ 1
So, the MATHSYSTEM introduces a function that equates 0.9999| with 1 and thereby closes the paradoxical loophole, such that we may continue using the MATHSYSTEM as a representation of the REALWORLDSYSTEM. Of course, just because we can mend one system so that it will represent another, does not indicate a necessary representative property of the former system in regards the latter, i.e., it does not show that the former system represents by necessity the latter system, but merely shows that it represents it, not necessarily by necessity.
Afterall, any system that represented necessarily another system would not need a function to close paradoxical loopholes, as such loopholes would not exist. The fact that the MATHSYSTEM has introduced such a function in an attempt to represent the REALWORLDSYSTEM, shows that the MATHSYSTEM is not necessarily representative of the REALWORLDSYSTEM.
But all these things arise, of course, because MATHSYSTEM is not in a necessary relationship with REALWORLDSYSTEM. Afterall, in REALWORLDSYSTEM 0.9999| v. 1 is a formality which is meaningless... how d'you say... gibberish.
Jon
And now you're off on your own again. I recommend the English language to you as a medium of communication.
Edited by Dr Adequate, : No reason given.

This message is a reply to:
 Message 120 by Jon, posted 01-24-2010 6:56 PM Jon has replied

Replies to this message:
 Message 122 by Jon, posted 01-24-2010 7:23 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 124 of 237 (544211)
01-24-2010 7:38 PM
Reply to: Message 122 by Jon
01-24-2010 7:23 PM


Re: Real Numbers and Real Ity
LOL. Whatever. When you have more to say other than "I don't get it", I will be ready to continue with you.
When you are willing to communicate in the English language, please feel free to continue.
As it is, you appear to be expressing your own mental confusion in a language of your own invention, the terms of which you have not troubled to define.
I cannot correct mistakes that you cannot even adequately express.

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 129 of 237 (544217)
01-24-2010 8:05 PM
Reply to: Message 128 by RAZD
01-24-2010 7:59 PM


Oh good grief ...
Look, the equivalence relation on decimal representations definitely puts every decimal representation in the same equivalence class as itself. 1 = 1. 4.9 = 4.9. The square root of two equals the square root of two.

This message is a reply to:
 Message 128 by RAZD, posted 01-24-2010 7:59 PM RAZD has replied

Replies to this message:
 Message 130 by RAZD, posted 01-24-2010 8:22 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 136 of 237 (544238)
01-25-2010 1:52 AM
Reply to: Message 130 by RAZD
01-24-2010 8:22 PM


Hi Dr A
Curiously you have just proven that you have not read my post in context.
It was intended as satire?

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 150 of 237 (544345)
01-25-2010 2:48 PM
Reply to: Message 144 by Stile
01-25-2010 9:27 AM


Re: Real Numbers and Real Ity
I don't understand this.
You went logically along until the very end. I don't (logically) see any reason why you put a "≠" in instead of a "=" at the end. What would make you do so?
He was c&p'ing a line from my demonstration that if we say that 0.9999| ≠ 1 then we embroil ourselves in a paradox.

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 158 of 237 (544383)
01-25-2010 7:04 PM
Reply to: Message 143 by RAZD
01-25-2010 7:33 AM


Re: ~
The proof was intended to show that 1 ≡ 0.999~ by assuming that it wasn't, and then showing that this results in a contradiction.
Mmm ... not really.
In the process it uses another version of 0.999~ and the problem is that if one is not 1 then the other isn't either and it remains half way between. One can't use the conclusion as part of the proof eh?
But that's not what's happening.
Look, call 0.9999~ x.
Then we have (1+x)/2 = x.
So 1 + x = 2x
i.e. 1 + x = x + x.
So 1 = x.

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 164 of 237 (544417)
01-26-2010 6:24 AM
Reply to: Message 162 by Huntard
01-26-2010 4:01 AM


What is it about math that makes people go mad, anyway? Or is it simply mad people that practice math?
Well, seriously, I don't think it's particularly an occupational hazard any more than for painters or poets or what-have-you.
But even then, I don't think that it's particularly a hazard for creative people. Psychologists used to call schizophrenia "truck-drivers' disease". Madness doesn't particularly strike down the highly creative, it's more that highly creative people are far more likely to have someone write their biographies. You are far more likely to find out that your favorite physicist has spent time in a mental hospital than you are to find out that the clerk at your local grocery store has done so, because no-one is prying into the life of the latter.
I remember when I stopped reading biographies of famous men. It was when I read a biographer of C. S. Lewis write that there was "no evidence" that his marriage was ever consummated.
What did he want, a bloody sheet?
Um ... I've gone far enough off topic, I'll shut up now.

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 Message 166 by onifre, posted 01-26-2010 8:54 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 167 of 237 (544430)
01-26-2010 11:03 AM
Reply to: Message 166 by onifre
01-26-2010 8:54 AM


Not true, there are studies that have shown a correlation between creativity and Bipolar disorders.
But what you have quoted is something beginning: "A number of people with creative talents have reportedly experienced hypomania".
OK, what proportion of people "with creative talents" (how is this quantified?) have "reportedly experienced hypomania", and what proportion of people without creative talents have "reportedly experienced hypomania"?

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 Message 166 by onifre, posted 01-26-2010 8:54 AM onifre has replied

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 170 of 237 (544444)
01-26-2010 1:00 PM
Reply to: Message 168 by AnswersInGenitals
01-26-2010 12:26 PM


Re: Trying to set things straight.
Now for a mea culpa. As erudite and definitive as the above sounds, there is a very good chance that I don't know what the hell I'm talking about.
This.
You might want to look up the term "open set".

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 176 of 237 (544493)
01-26-2010 8:03 PM
Reply to: Message 173 by Jon
01-26-2010 6:04 PM


Re: Totally right!
I think there is a fine difference between growing to infinity and infinitely growing. I would say that the latter is possible in respects 0.9, etc., while still maintaining it has a value less than 1.0. Afterall, the number we are working with is infinite, is it not?
NO.
I see no reason why Math could not permit such infinite divisions in contradiction to Reality, which clearly does not. (Damn, there's that 'Zeno' whisper sound again.) Now, I realize that it doesn't work this way, and so long as the MATHSYSTEM maintains the DISTINCTness criterion it too will not permit such infiniteness. But that it needs a check-sub-system to eliminate contradictions with Reality should be a good sign that the MATHSYSTEM and its parts do not follow necessarily from Reality (REALWORLDSYSTEM), just that we have found a way to make the system both internally consistent and eliminate its contradictions to Reality. Anyway, more on this relationship when my dern thread gets (if ever) promoted.
Pure gibberish.

This message is a reply to:
 Message 173 by Jon, posted 01-26-2010 6:04 PM Jon has replied

Replies to this message:
 Message 178 by Jon, posted 01-26-2010 8:13 PM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 179 of 237 (544500)
01-26-2010 9:44 PM
Reply to: Message 178 by Jon
01-26-2010 8:13 PM


Re: Totally right!
It's not?
Of course not.
How many decimal places does 0.9999| go out to?
Infinitely many, of course.

This message is a reply to:
 Message 178 by Jon, posted 01-26-2010 8:13 PM Jon has replied

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Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 193 of 237 (544589)
01-27-2010 11:29 AM
Reply to: Message 190 by Rrhain
01-27-2010 6:44 AM


Infinity - infinity is undefined.
Not at all. A set is infinite if and only if it is the same size as (i.e. can be put into a one-to-one correspondence with) a proper subset of itself.

This message is a reply to:
 Message 190 by Rrhain, posted 01-27-2010 6:44 AM Rrhain has replied

Replies to this message:
 Message 200 by Rrhain, posted 01-31-2010 7:05 AM Dr Adequate has replied

  
Dr Adequate
Member (Idle past 315 days)
Posts: 16113
Joined: 07-20-2006


Message 203 of 237 (545173)
02-02-2010 12:45 AM
Reply to: Message 200 by Rrhain
01-31-2010 7:05 AM


I read what you intended to be a minus sign as a dash.

This message is a reply to:
 Message 200 by Rrhain, posted 01-31-2010 7:05 AM Rrhain has replied

Replies to this message:
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