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#251
08-06-2012, 05:38 AM
 Giles Charter Member Join Date: Apr 2004 Location: Newcastle NSW Posts: 11,562
Quote:
 Originally Posted by erik150x Also putting limits aside, it could very well be I think.. that 1/2 + 1/4 + 1/8 + ... + 1/infinity = 1 but 9/10 + 9/100 + 9/1000 + ... + 9/infinity < 1
But every term in that first series is less than the corresponding term in the second:

1/2 < 9/10
3/4 < 99/100
7/8 < 999/1000
15/16 < 9999/10000

It would be very odd if the limit of the first were greater than the limit of the second, since it can never overtake it. (But it's not odd that they have the same limit.)
#252
08-06-2012, 05:39 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope Your problem is getting hung up on the notion of a limit. I keep telling you, fuck limits. Limits are not relevant here. We are going to infinity and beyond. Any limit notation is necessary because we don't have the tools to deal directly with infinities. But that's what you're proposing that we do with your infinite decimal. Accordingly, we have to take off the gloves and go mano-a-mano with your decimal representation and say what is it's value AT infinity - NO LIMIT NOTATION.
I love you man.

Most especially for this: "Any limit notation is necessary because we don't have the tools to deal directly with infinities"
#253
08-06-2012, 05:43 AM
 allotrope Guest Join Date: Jun 2012
That's very kind, but I'll be happier if this all seems to be a little more real a little less like some sleazy math trick to you.

Yes? No?

Last edited by allotrope; 08-06-2012 at 05:44 AM.
#254
08-06-2012, 05:45 AM
 erik150x Guest Join Date: Aug 2012
The value of .999... at infinity is .999... or if you prefer 1 - 1/infinity. Yes I realize 1/infinity is undefined, and no I can;t precisely definie it. But someone shoudl get busy on it ;-)
#255
08-06-2012, 05:46 AM
 Giles Charter Member Join Date: Apr 2004 Location: Newcastle NSW Posts: 11,562
Quote:
 Originally Posted by erik150x This idea " For any two real numbers there is one in-between." is imposed by the definiton of real numbers which uses Limits. At least that is my understanding of things.
No, it's imposed by two things:
(1) the ordinary rules of arithmetic, and
(2) the fact that the sum of two real numbers and half of a real number are real numbers themselves.
Limits are quite irrelevant.

From that, if x<y then x<(x+y)/2<y, i.e., (x+y)/2 is a real number between x and y not equal to either.

It's a bit harder to prove that between any two real numbers there is a rational number, but that theorem isn't really relevant here.
#256
08-06-2012, 05:47 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope That's very kind, but I'll be happier if this all seems to be a little more real a little less like some sleazy math trick to you. Yes? No?
Oh yes yes please! :-D

I mean that if you can show me how .999... = 1 without limits I will be very happy!
#257
08-06-2012, 05:49 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Giles No, it's imposed by two things: (1) the ordinary rules of arithmetic, and (2) the fact that the sum of two real numbers and half of a real number are real numbers themselves. Limits are quite irrelevant. From that, if x
Can you explain to me why 1 and 2 must be true?

what ordinary rules of arithmetic?

I am not sure how 2) applys here?

Last edited by erik150x; 08-06-2012 at 05:51 AM.
#258
08-06-2012, 05:53 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x Oh yes yes please! :-D I mean that if you can show me how .999... = 1 without limits I will be very happy!
OK, well, that was what all of the "at infinity" stuff was about.

But I'm guessing your response will be something along the lines of even at infinity there will still be an infinitely small difference.

Except, at infinity, no, even that infinitely small difference has been gobbled up by all of those repeating 9's.

You have gone out to infinity such that there is no end to the decimal where you could find that infinitesimal difference. It's gone, buried in infinity.

Sorry, but that's about the best I can do by way of an explanation.

Last edited by allotrope; 08-06-2012 at 05:55 AM.
#259
08-06-2012, 05:58 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Giles But every term in that first series is less than the corresponding term in the second: 1/2 < 9/10 3/4 < 99/100 7/8 < 999/1000 15/16 < 9999/10000 It would be very odd if the limit of the first were greater than the limit of the second, since it can never overtake it. (But it's not odd that they have the same limit.)
#260
08-06-2012, 06:01 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope OK, well, that was what all of the "at infinity" stuff was about. But I'm guessing your response will be something along the lines of even at infinity there will still be an infinitely small difference. Except, at infinity, no, even that infinitely small difference has been gobbled up by all of those repeating 9's. You have gone out to infinity such that there is no end to the decimal where you could find that infinitesimal difference. It's gone, buried in infinity. Sorry, but that's about the best I can do by way of an explanation.
Well, thanks for trying. Sorry I just don't see it. All I can see is something infinitly close to 1, but not 1.
#261
08-06-2012, 06:13 AM
 Ruminator Guest Join Date: Dec 2007
Quote:
 Originally Posted by erik150x But limits don't explain how this is true. They just say at Infinity they become equal. No how or why? That's what I want. And that's whats missing from Limits.
Limits don't have to explain it as a satisfying concrete or metaphysical answer. We don't have to get "comfortable" with it in that sense at all. The notion of limits is simply an idea that is consistent with itself; from that, we can then hang subsequent consistent ideas from it.

Instead of asking "limits" to "explain" or "understand" infinity. We only ask that limits be a usable tool for "working with" infinity. This is much more reasonable goal!

As a comparison, consider something as basic as a line mathematics.

Most of us just "accept" this mathematical idea of a "line" without giving it a lot of thought. But what exactly is a line? Can we construct it?

Is a piece of string drawn pull tight like a guitar string a "line"? No, that doesn't meet the definition of a line. How about a thin laser beam? Nope. Even a line that is the width of 1 electron is not a true "line" in the the mathematical sense. A mathematical line has zero width.

If we say a line is is a set of infinite points with zero width, how can we even create statements such as "2 parallel lines never meet" ... the non-mathematical mind can retort, "well sure, 2 of impossible and incomprehensible items of zero width never meet, duh!" Imagine a inquisitive child trying to drill down this line of reasoning to its very end. You must explain that it's not possible to "think" of lines like that because it leads to writing English sentences that are meaningless.

If we can't even construct lines, how do we comprehend it on some satisfying metaphysical sense? We don't. A line is simply an idea we work with. (Same as limits.)

Another example... on a piece of paper, we can write the number 1 x 1081 which is a number larger than the number of atoms in the universe. This number is incomprehensible.

Even with that difficulty, how can we claim: (1 x 1081 + 1) > (1 x 1081)

It's only the rules of addition that says that's statement is true. We can't arrange a pile of 1 x 1081 apples (or atoms) and visually see that one heap is obviously 1 bigger than the other.

If we can accept mathematical definitions of "lines" and rules of addition on incomprehensibly large numbers, we can also accept the concept of "limits" and that .999... = 1.
#262
08-06-2012, 06:16 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x Well, thanks for trying. Sorry I just don't see it. All I can see is something infinitly close to 1, but not 1.
OK, let's try one more thing.

For there to be a difference, you need to be able to subtract your decimal from 1 - correct?

Now, in order for you to do that, don't you have to be able to find the tail end of the decimal?

But at infinity, there is no tail end because . . . wait for it . . . you're AT infinity.

Are you feelin' any love yet?
#263
08-06-2012, 06:18 AM
 erik150x Guest Join Date: Aug 2012
Between Giles and Allotrope they make a compelling case as to why intuitvely I should expect .999... to eqaul 1. But Limit theory just is less than satisfying. It says nothing about how or why... just that it does. It leaves me thinking perhaps .999... does = 1. Yet it seems such a fundimental issue, that the fact we have no proof troubles me. To me limits hide our ignorance in this matter.

As Allotrope says "It's gone, buried in infinity" -- okay maybe it is, but thats to me as vague as 1/infinity.
#264
08-06-2012, 06:22 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Ruminator Limits don't have to explain it as a satisfying concrete or metaphysical answer. We don't have to get "comfortable" with it in that sense at all. The notion of limits is simply an idea that is consistent with itself; from that, we can then hang subsequent consistent ideas from it. Instead of asking "limits" to "explain" or "understand" infinity. We only ask that limits be a usable tool for "working with" infinity. This is much more reasonable goal! As a comparison, consider something as basic as a line mathematics. Most of us just "accept" this mathematical idea of a "line" without giving it a lot of thought. But what exactly is a line? Can we construct it? Is a piece of string drawn pull tight like a guitar string a "line"? No, that doesn't meet the definition of a line. How about a thin laser beam? Nope. Even a line that is the width of 1 electron is not a true "line" in the the mathematical sense. A mathematical line has zero width. If we say a line is is a set of infinite points with zero width, how can we even create statements such as "2 parallel lines never meet" ... the non-mathematical mind can retort, "well sure, 2 of impossible and incomprehensible items of zero width never meet, duh!" Imagine a inquisitive child trying to drill down this line of reasoning to its very end. You must explain that it's not possible to "think" of lines like that because it leads to writing English sentences that are meaningless. If we can't even construct lines, how do we comprehend it on some satisfying metaphysical sense? We don't. A line is simply an idea we work with. (Same as limits.) Another example... on a piece of paper, we can write the number 1 x 1081 which is a number larger than the number of atoms in the universe. This number is incomprehensible. Even with that difficulty, how can we claim: (1 x 1081 + 1) > (1 x 1081) It's only the rules of addition that says that's statement is true. We can't arrange a pile of 1 x 1081 apples (or atoms) and visually see that one heap is obviously 1 bigger than the other. If we can accept mathematical definitions of "lines" and rules of addition on incomprehensibly large numbers, we can also accept the concept of "limits" and that .999... = 1.
We can prove by though the mehtod of induction that since 1 + 1 = 2 that 1 + 2 =3 and so on. It is not just a given, only 1 + 1 = 2 is the given there. I am pretty sure set theory takes care of 1 + 1 = 2 to start things out.

So thats not a fair compairison to the assumptions of Limits.
#265
08-06-2012, 06:26 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope OK, let's try one more thing. For there to be a difference, you need to be able to subtract your decimal from 1 - correct? Now, in order for you to do that, don't you have to be able to find the tail end of the decimal? But at infinity, there is no tail end because . . . wait for it . . . you're AT infinity. - Are you feelin' any love yet?
How can you say it's Zero then? That is if you can't find the tail end to do the subtraction. You want to place the burden of proof on me to say that 1 - .999... does not equal zero. I could do the same in return. Saying you can't find the tail end to do the subtraction therefor it must be just forgotten about doesn't settle well with me.

Last edited by erik150x; 08-06-2012 at 06:27 AM.
#266
08-06-2012, 06:30 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x How can you say it's Zero then? That is if you can't find the tail end to do the subtraction. You want to place the burden of proof on me to say that 1 - .999... does not equal zero. I could do the same in return. Saying you can't find the tail end to do the subtraction therefor it must be just forgotten about doesn't settle well with me.
No, what I'm saying is that since there is no tail, there is no difference to find.

I was using the subtraction example to make it feel more concrete.

But the point really is that to find that tiny difference you have to keep hopping from one 9 to the next ad infinitum. Therefore, if you can never actually FIND the difference, no difference exists.
#267
08-06-2012, 06:32 AM
 erik150x Guest Join Date: Aug 2012
Okay you guys have worn me down for now. I have to try and get an hour or so of sleep before work. :-(
#268
08-06-2012, 06:33 AM
 Ruminator Guest Join Date: Dec 2007
Quote:
 Originally Posted by erik150x So thats not a fair compairison to the assumptions of Limits.
So how do you "accept" the mathematical concept of a 1-dimensional line with zero width?

Last edited by Ruminator; 08-06-2012 at 06:34 AM.
#269
08-06-2012, 06:35 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope No, what I'm saying is that since there is no tail, there is no difference to find. I was using the subtraction example to make it feel more concrete. But the point really is that to find that tiny difference you have to keep hopping from one 9 to the next ad infinitum. Therefore, if you can never actually FIND the difference, no difference exists.
I dont think the numbers care if we can find them. They do their thing regardless ;-)

I think 1 + 1 = 2 before we ever convcieved of a number.

Last edited by erik150x; 08-06-2012 at 06:36 AM.
#270
08-06-2012, 06:39 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Ruminator So how do you "accept" the mathematical concept of a 1-dimensional line with zero width?
At this point I am not even sure what a line is. I mean every 2 points on a line has to have a point between them right? So pick any 2 points and there are so many levels of infinity between those points, I get dizzy. But none of them can touch each other right? Becuase if they did then that number - the number touching it would = 0, so they would be the same point... no? Not real?

You tell me what a line is.

Last edited by erik150x; 08-06-2012 at 06:42 AM.
#271
08-06-2012, 06:40 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x I dont think the numbers care if we can find them. They do their thing regardless ;-) I think 1 + 1 = 2 before we ever convcieved of a number.
Oh come now. Obviously I didn't mean it in any kind anthropomorphized sense. Jeez.

Pls re-read what I said if that's really what you believe.
#272
08-06-2012, 07:07 AM
 Monimonika Guest Join Date: Aug 2012
Quote:
 Originally Posted by erik150x Response to Monimonika: .999...9 + .999...9 ----------- 1.999...8 + .999...9 ----------- 2.999...7 + .999...9 ----------- 3.999...6 + .999...9 ----------- 4.999...5 + .999...9 ----------- 5.999...4 + .999...9 ----------- 6.999...3 + .999...9 ----------- 7.999...2 + .999...9 ----------- 8.999...1 + .999...9 ----------- 9.999...0
Sorry, don't have time to read all of the other comments, but if this is how you think non-terminating rational numbers are constructed, then the way you (not me, not anyone else) do long division is the following:

Let's divide 1 by 9:

**0.111111111.....1
**_______________
9/ 1.0000000000....0
*-0
**10
**-9
***10
***-9
****1
*******etc.
*************10
*************-9
**************1
STOP!! I (erik150) will arbitrarily stop here and discard the remainder so that I can have the result end with a 1.
This is also why my (erik150's) intuition is skeptical that 0.333... is equal to 1/3, since the removal of the remainder necessarily makes 1/3 > 0.333... (or rather, 1/3 > 0.333...3)!

erik150, you really need to understand that there is NO END to the number of decimal places to the right of the decimal point. It's like saying "infinity" is just some humongous finite number that you simply stopped bothering to count. I mean, what's stopping me from just going one more step in the above division? Why the stopping point?
#273
08-06-2012, 08:27 AM
 erik150x Guest Join Date: Aug 2012
Proof Limit Definiton Contradticts Itself...?

Ok first I haven't read any posts since my last. I have been trying to sleep. But I had to post this while it's in my mind.

Let's assume Limit Theory is correct. .999 = 1
And for that matter 1/2 + 1/4 + 1/8 + ... = 1

Now picture 2 horizontial parrallel line segements, A and B.
A direclty above B.
for fun lets say these lines are a mile long (it doesn't really matter)

Each line segment is labeled A1 and B1 on the left most point
Each line segment is labeled A2 and B2 on the right most point

We can divide a line segment into an infinite number of points right?
So we do this for both lines. Making sure each point on the top line, lines up with the bottom line.

On the top line I will lablel each point as follows 1 . 0 0 0 . . .
On the bottom line I will label each point as follows 0. 9 9 9 . . .

How can I do this? Right how can I label 2 infinite lines?
Well to make things simple let's assume I am marking line A with my left hand and line B with my right. So I only have to make one pass. And I will only decribe marking line A, but it assumed I am marking line B at each point as well.

I make my first mark at the half mile point, and put (1.). then at the 3/4 mile mark 0, then at the 7/8 mile mark 0, then at the 15/16 mile mark 0, etc...

Each mark takes me 1/2 the time to get to since I am traveling half the distance each time. So lets say it takes me 30 mins to get to the first mark then 15 mins to get to the second mark, 7 mins 30 secs for the 3rd and so on.

I think most can see where I am going with this, but I will go on...

According to limit theory I can travel to the end in 1 hour marking an infinite number of points.
1/2 HOUR + 1/4 HOUR + 1/8 HOUR + ... = 1 HOUR

And that consists of an infinite number of points.

Now I have my lines both labeled. To review as such:
On the top line I will lablel each point as follows 1 . 0 0 0 . . .
On the bottom line I will label each point as follows 0. 9 9 9 . .

Can I really physycally do this? Of course not, but this is just a thought experiment so bear with me. I ceartainly can walk a mile in one hour and one could certainly imagine two lines with these points exisintg as they do on lines. Furthermore whether I actually labled them or not, does it really matter? The point is I can get to them and pass them all in 1 hour easily.

Now we reverse the process and start subtracting line B from A. To be honest do we really need to finish the whole calculation? Because once we see the 0 at the end of line A and the 9 at the end of line B, we know what the result will be:
.000...1

So it seems we can in a theoretical way find the end of these numbers and do the math.

But the math contradicts what limit theory tells us the answer should be which would be:
.000...0

I guess this is all a fanciful way of saying it in the land of math we can get to the end of the line as sure as we can walk across the room. Calculating an infinite number of decimal places is a snap.

I could be deleriously tired, but it makes sense to me.
#274
08-06-2012, 08:36 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Monimonika Sorry, don't have time to read all of the other comments, but if this is how you think non-terminating rational numbers are constructed, then the way you (not me, not anyone else) do long division is the following: Let's divide 1 by 9: **0.111111111.....1 **_______________ 9/ 1.0000000000....0 *-0 **10 **-9 ***10 ***-9 ****1 *******etc. *************10 *************-9 **************1 STOP!! I (erik150) will arbitrarily stop here and discard the remainder so that I can have the result end with a 1. This is also why my (erik150's) intuition is skeptical that 0.333... is equal to 1/3, since the removal of the remainder necessarily makes 1/3 > 0.333... (or rather, 1/3 > 0.333...3)! erik150, you really need to understand that there is NO END to the number of decimal places to the right of the decimal point. It's like saying "infinity" is just some humongous finite number that you simply stopped bothering to count. I mean, what's stopping me from just going one more step in the above division? Why the stopping point?
Yeah, I don't follow what point your tryign to make. You posted something about adding .999... to itself 10 times to simulate multiplication by 10. Which you can't really do without limits. I think you need to go back to the post of yours I was repsonding to. And also the fact that in either case they are on shakey ground. But you want to just ignore all the decimal places beyond some unamed limit?

Maybe we are just not connecting with each other here. I don't know why there is need to bring the construction of reals or divison into this? We were simply tlaking about adding already existing numbers. Namely .999... and 10 of them.
#275
08-06-2012, 08:57 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x So it seems we can in a theoretical way find the end of these numbers and do the math.
No, because by definition, that's a term of art by the way, by definition, if you could label all of the points, then there were not an infinite number.

You know dude, if you just don't WANT to understand, that's fine, but at least be honest about it, m'kay?
#276
08-06-2012, 09:11 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope No, because by definition, that's a term of art by the way, by definition, if you could label all of the points, then there were not an infinite number. You know dude, if you just don't WANT to understand, that's fine, but at least be honest about it, m'kay?
As I said... do I really need to label them?

As we discussed before to get from point A to point B, you must go half way 1st right? And 1/2 of the remaining distance and so on... this is the classic Zeno's paradox which is solved by saying
1/2 + 1/4 + 1/8 + ... = 1
is it not? Is there not an infinite number of steps involved there? Do we clearly not move across the room form point A ot point B? Is there theoretically not an infinit number of points there? Do I really have to label them? All i need to do is reach the last one, labeling them is not really neccessary.

We have reached the end of an infinite number of points stecteched along this mile line line segment. We already know how they should be labeled, do we not? Do you susggest at some point in this process I would (if I was actually marking them), stop marking zero's on top or stop marking nine's on the bottom?

The point is we can find the end of an infinite number of points, and that's all we really need to do here.

I'm not trying to not understand? Please tell me where my logic is wrong here?
#277
08-06-2012, 09:14 AM
 TATG Guest Join Date: Aug 2008
Quote:
 Originally Posted by allotrope No, because by definition, that's a term of art by the way, by definition, if you could label all of the points, then there were not an infinite number.
Usually I would think it meant not more than countably many, which does not mean not an infinite number, so I don't know what you are on about.
#278
08-06-2012, 09:17 AM
 Frylock Guest Join Date: Jun 2001
It's not that the equation of .999... with 1 is "built in" to the system we use as an "assumption." Rather, it's a logical result of the definitions used at the foundation of that system. You can prove it--using the assumptions we all use when we use the decimal number system.

And it is in fact true, in the sense that in the system we are using when we use the decimal number system, the quantity represented by the expression ".999..." is the very same quantity as that represented by the expression "1".

Maybe you already know both of those things, but you've said things lately which seem to indicate you think otherwise so I want to be sure this is clear.

In a system wherein .999... =/= 1, the expression ".999..." does not represent the same quantity that the expression ".999..." represents in the normal decimal number system. It represents some other quantity. (In fact, it may not represent a "quantity" at all in the colloquial sense. It depends on the model.)

I think.
#279
08-06-2012, 09:18 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x As I said... do I really need to label them? As we discussed before to get from point A to point B, you must go half way 1st right? And 1/2 of the remaining distance and so on... this is the classic Zeno's paradox which is solved by saying 1/2 + 1/4 + 1/8 + ... = 1 is it not? Is there not an infinite number of steps involved there? Do we clearly not move across the room form point A ot point B? Is there theoretically not an infinit number of points there? Do I really have to label them? All i need to do is reach the last one, labeling them is not really neccessary. We have reached the end of an infinite number of points stecteched along this mile line line segment. We already know how they should be labeled, do we not? Do you susggest at some point in this process I would (if I was actually marking them), stop marking zero's on top or stop marking nine's on the bottom? The point is we can find the end of an infinite number of points, and that's all we really need to do here. I'm not trying to not understand? Please tell me where my logic is wrong here?
Your logic is flawed because you still fail to understand what infinity means.

Let's put a little '9' at each halfway mark. There will still be an infinite number of them. As I said before, YOU NEVER GET TO POINT B EXCEPT AT INFINITY.

It's not my fault if you don't read my posts now is it?
#280
08-06-2012, 09:24 AM
 TriPolar Member Join Date: Oct 2007 Location: rhode island Posts: 19,805
Quote:
 Originally Posted by Frylock It's not that the equation of .999... with 1 is "built in" to the system we use as an "assumption." Rather, it's a logical result of the definitions used at the foundation of that system. You can prove it--using the assumptions we all use when we use the decimal number system. And it is in fact true, in the sense that in the system we are using when we use the decimal number system, the quantity represented by the expression ".999..." is the very same quantity as that represented by the expression "1". Maybe you already know both of those things, but you've said things lately which seem to indicate you think otherwise so I want to be sure this is clear. In a system wherein .999... =/= 1, the expression ".999..." does not represent the same quantity that the expression ".999..." represents in the normal decimal number system. It represents some other quantity. (In fact, it may not represent a "quantity" at all in the colloquial sense. It depends on the model.) I think.

I don't know a lot of maths, but your explanation is concise, and I don't find much to argue about here. When .999... is used, it's used in place of 1. It indicates to me that a faulty algorithm that results in an endless loop, producing 9's forever, but the value it's trying to produce is 1.

As far as .999....1 goes, it's pretty easy to understand that there are an infinite number of numbers between 1 and 2, yet 2 still follows 1. I don't know what to do with .999...1, but it doesn't seem difficult to understand.
#281
08-06-2012, 09:25 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope Your logic is flawed because you still fail to understand what infinity means. Let's put a little '9' at each halfway mark. There will still be an infinite number of them. As I said before, YOU NEVER GET TO POINT B EXCEPT AT INFINITY. It's not my fault if you don't read my posts now is it?
Right the last point on the both line segments, the infinite point at the end of both line segment A and B? Can I not walk from one end of the line segment to the other?

Do I not pass an infinite number of 0s on top and 9s on the bottom by time I reach the end of the line.

Each half way point represents a number on top and bottom.

1/2 + 1/4 + 1/8 +... + 1/infinity = 1 This is the classic Limit soultion to Zeno's paradox? Is there not an infinite number of points here?

Please tell me where the logic is wrong?
#282
08-06-2012, 09:30 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x Right the last point on the both line segments, the infinite point at the end of both line segment A and B? Can I not walk from one end of the line segment to the other? Do I not pass an infinite number of 0s on top and 9s on the bottom by time I reach the end of the line. Each half way point represents a number on top and bottom. 1/2 + 1/4 + 1/8 +... + 1/infinity = 1 This is the classic Limit soultion to Zeno's paradox? Is there not an infinite number of points here? Please tell me where the logic is wrong?
I just did, what part didn't you understand?
#283
08-06-2012, 09:30 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope Your logic is flawed because you still fail to understand what infinity means. Let's put a little '9' at each halfway mark. There will still be an infinite number of them. As I said before, YOU NEVER GET TO POINT B EXCEPT AT INFINITY. It's not my fault if you don't read my posts now is it?
You did not try to really understand my post. The Line segment is 1 mile (not infinite) so I can reach the end as people aften do go for walks. But we all know you must always go halfway first then half of the reaminder and so on...
This is an infinite series represented by
1/2 + 1/4 + 1/8 + ... + 1/infinity = 1
In both distance and time I have taveled:

I have reached an infinite number of points, yes or no?
#284
08-06-2012, 09:31 AM
 TATG Guest Join Date: Aug 2008
Quote:
 Originally Posted by erik150x Now we reverse the process and start subtracting line B from A. To be honest do we really need to finish the whole calculation? Because once we see the 0 at the end of line A and the 9 at the end of line B, we know what the result will be: .000...1
There is no last numeral.

Last edited by TATG; 08-06-2012 at 09:32 AM.
#285
08-06-2012, 09:33 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope I just did, what part didn't you understand?
You said:
Your logic is flawed because you still fail to understand what infinity means. -- this is a useless counter, means nothing... except your opinon of my knowledge. Nothing about the actual logic I stated.

Let's put a little '9' at each halfway mark. There will still be an infinite number of them. As I said before, YOU NEVER GET TO POINT B EXCEPT AT INFINITY. ---
How did I not reach an infinite number of points on my walk?

It's not my fault if you don't read my posts now is it? -- again usless counter statement.
#286
08-06-2012, 09:34 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x You did not try to really understand my post. The Line segment is 1 mile (not infinite) so I can reach the end as people aften do go for walks. But we all know you must always go halfway first then half of the reaminder and so on... This is an infinite series represented by 1/2 + 1/4 + 1/8 + ... + 1/infinity = 1 In both distance and time I have taveled: I have reached an infinite number of points, yes or no?
Are you going by 1/2 each time? I'll assume yes.
Are you labeling a point each time? I'll assume yes.

In that case, it will take you an infinite amount of time and you will hit an infinite number of points.

You will still never reach point B except at infinity.

Is that better?
#287
08-06-2012, 09:34 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by TATG There is no last numeral.
But I Just told you how to find the last numeral. Please tell me how I my method is wrong?
#288
08-06-2012, 09:34 AM
 Francis Vaughan Guest Join Date: Sep 2009
You are solving Zeno by appealing to motion in the physical world - yet you are claiming that you physically were able to generate the labelled points - and you do have to label them all because you claim that the "last" point is the one that matters. You are thus confusing together an appeal to physical motion with an infinite process. But you need to provide a solution to Zeno in the abstract that allows your labelling to work. Placing the intervals in a one to one relationship with the fractions of time needed to label them is the usual solution - but you need to then show that time reaches the end - thus you are trying to prove something by assuming its converse. Why should the time fractions reach the end point and not the fractional distances? Either place both or neither in the physical world - you can't place one in the physical and the other in the abstract.
#289
08-06-2012, 09:35 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope Are you going by 1/2 each time? I'll assume yes. Are you labeling a point each time? I'll assume yes. In that case, it will take you an infinite amount of time and you will hit an infinite number of points. You will still never reach point B except at infinity. Is that better?
I already stated twice ... once in the problem and aftwards. It is not really neccessary to label them. We already knwo what they should be. I really just need to reach the last one.

Last edited by erik150x; 08-06-2012 at 09:36 AM.
#290
08-06-2012, 09:36 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by Francis Vaughan You are solving Zeno by appealing to motion in the physical world - yet you are claiming that you physically were able to generate the labelled points - and you do have to label them all because you claim that the "last" point is the one that matters. You are thus confusing together an appeal to physical motion with an infinite process. But you need to provide a solution to Zeno in the abstract that allows your labelling to work. Placing the intervals in a one to one relationship with the fractions of time needed to label them is the usual solution - but you need to then show that time reaches the end - thus you are trying to prove something by assuming its converse. Why should the time fractions reach the end point and not the fractional distances? Either place both or neither in the physical world - you can't place one in the physical and the other in the abstract.
Silly boy thinks he's turning an example I used to try to help him back on me. He doesn't realize whatever kind of infinity we use to map this out, it's all the same.

Last edited by allotrope; 08-06-2012 at 09:38 AM.
#291
08-06-2012, 09:37 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x I already stated twice ... once in the problem and aftwards. It is not really neccessary to label them. We already knwo what they should be. I really just need to reach the last one.
And with an infinite number of them BY DEFINITION there is no LAST ONE.

Last edited by allotrope; 08-06-2012 at 09:39 AM.
#292
08-06-2012, 09:38 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by Francis Vaughan You are solving Zeno by appealing to motion in the physical world - yet you are claiming that you physically were able to generate the labelled points - and you do have to label them all because you claim that the "last" point is the one that matters. You are thus confusing together an appeal to physical motion with an infinite process. But you need to provide a solution to Zeno in the abstract that allows your labelling to work. Placing the intervals in a one to one relationship with the fractions of time needed to label them is the usual solution - but you need to then show that time reaches the end - thus you are trying to prove something by assuming its converse. Why should the time fractions reach the end point and not the fractional distances? Either place both or neither in the physical world - you can't place one in the physical and the other in the abstract.
I have put forth I do not need to label them, we know what they should be labeled they are the same all the way to the end. In fact the whole argument rests on simple reaching the end of an infinite series of points. which I will associate with numerals, but there is no need to physically label them, why should there be?
#293
08-06-2012, 09:39 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope And with and infinite number of them BY DEFINITION there is no LAST ONE.
Again I have given you instructions on how to find it. What part of those instructions are flawed?

Again, there is no need to physically label them, why should there be?
#294
08-06-2012, 09:41 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x I have put forth I do not need to label them, we know what they should be labeled they are the same all the way to the end. In fact the whole argument rests on simple reaching the end of an infinite series of points. which I will associate with numerals, but there is no need to physically label them, why should there be?
The fact that you could even say something like "reaching the end of and infinite series" with a straight face, is really . . . I don't even know what to say.
#295
08-06-2012, 09:42 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x Again I have given you instructions on how to find it. What part of those instructions are flawed? Again, there is no need to physically label them, why should there be?
Your concept is flawed - there is no last one in an infinite series - that's why they call it INFINITE.

You can't really be this thick. I don't mean to be rude but that is just too over the top.
#296
08-06-2012, 09:43 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope The fact that you could even say something like "reaching the end of and infinite series" with a straight face, is really . . . I don't even know what to say.
So tell me then how do you solve Zeno's paradox of moving from point A to point B?

Since the distince is infinitely divisible in halves, you must pass or reach an infinite number of them no?
#297
08-06-2012, 09:44 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x So tell me then how do you solve Zeno's paradox of moving from point A to point B? Since the distince is infinitely divisible in halves, you must pass or reach an infinite number of them no?
I've told you 3 times already. After this, I'm outta here.

YOU NEVER GET TO B - you only get there at infinity.
#298
08-06-2012, 09:46 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope I've told you 3 times already. After this, I'm outta here. YOU NEVER GET TO B - you only get there at infinity.
So you can't move? Thats shame. I am sorry you can never get from pont A to point B? Your whole life must be an illusion?
#299
08-06-2012, 09:49 AM
 allotrope Guest Join Date: Jun 2012
Quote:
 Originally Posted by erik150x So you can't move? Thats shame. I am sorry you can never get from pont A to point B? Your whole life must be an illusion?
You continue to move but in every smaller increments. When the number of increments reach infinity, you arrive at point B.
#300
08-06-2012, 09:50 AM
 erik150x Guest Join Date: Aug 2012
Quote:
 Originally Posted by allotrope You continue to move but in every smaller increments. When the number of increments reach infinity, you arrive at point B.
Thank you. So we agree as I moved from the start of my walk to the end, I did indeed reach an infinit number of points each 1/2 the distance of the previous?

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