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## #26 2012-10-24 20:20:15

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Infinity multiplied by infinity

Mathematics is very much like a game, you start from a few simple rules and proceed from there following the rules, All they would have to do is change some rules.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #27 2012-10-24 20:38:01

Mpmath
Member
Registered: 2012-10-11
Posts: 216

### Re: Infinity multiplied by infinity

But if infinity will be eliminate, numbers will be infinite or not?

Winter is coming.

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## #28 2012-10-24 20:44:37

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Infinity multiplied by infinity

Numbers would be transfinite. They argue there is no sense in having a symbol that there is no model for in the real world. The universe is finite. Numbers need not go to infinity, just to the largest number we can currently store in a computer.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #29 2012-10-24 20:59:27

Mpmath
Member
Registered: 2012-10-11
Posts: 216

### Re: Infinity multiplied by infinity

If we will find the largest number we can  currently store in a computer, we can plus 1 and we will have Another largest number.

Winter is coming.

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## #30 2012-10-24 21:02:40

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

But we wouldn't have purposefor that number.

But we could take something more obvious to be the largest number we need- Grahams number. It is the largest number to have a proper mathematical meaning.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #31 2012-10-24 21:06:43

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Infinity multiplied by infinity

Proper mathematical meaning? It stands for nothing real, therefore it is an abstraction. A computer cannot hold it. It does not fit their idea.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #32 2012-10-26 17:07:36

Calligar
Member
Registered: 2011-09-24
Posts: 272

### Re: Infinity multiplied by infinity

I don't know, I myself would argue that infinity should not be taken out of mathematics, though I would agree that it can stir up a lot of confusion at times.  Infinity is not that hard to understand, the majority of people who misunderstand infinity see it as a number, which is where a lot of the...confusion for many is.

As for the specific use for it, I would argue there it is more likely there is no current necessity for it, but that doesn't mean that that won't matter in the future.  The way I see it, everything in mathematics has not yet been discovered, knowledge itself is infinite, we know only a limited amount of it, and that amount we know increases throughout time (this can be said for knowledge in general, not only mathematics).  By the way, that last statement is not a fact, it is an opinion, my opinion.  I apologize if what I say you don't agree with, that statement was not meant to insult anyone who thinks otherwise.

But anyway, with that, there might be cases where infinity is necessary in the future, on top of that, we do currently use it (though not sure about how necessary it is currently, as bobbym seems to be suggesting it's not necessary anywhere currently).  Even with changing the idea to fit better into mathematics, the way I see it, that would in turn be a different concept, still not reason to take out the current infinity concept.

As for the on-topic question, if it weren't cleared up already (which it seems like it has), I can further argue where you go wrong if you are still confused about it.

There are always other variables.  -[unknown]
But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end.  -Aristotle
Everything makes sense, one only needs to figure out how.  -[unknown]

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## #33 2012-10-26 20:17:35

Mpmath
Member
Registered: 2012-10-11
Posts: 216

### Re: Infinity multiplied by infinity

I agree with you. I see infinity like a way to define our universe. As I said before if we find the biggest number in the world we can add one and we will have a new number, bigger than the previous number. So we can go on we will never find a final result, but we can't prove that infinity exists because we will never reach infinity, in each field of science. We can only theorize his existence, But I think that infinity is a fundamental concept for understand mathematics.

Winter is coming.

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## #34 2012-10-26 20:18:14

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Infinity multiplied by infinity

Hi;

as bobbym seems to be suggesting it's not necessary anywhere currently

Nope. Personally, I think it should stay. I love watching set theorists and topologists ( algebraic and geometric ) suffer.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #35 2012-10-26 22:05:13

bob bundy
Registered: 2010-06-20
Posts: 8,354

### Re: Infinity multiplied by infinity

hi,

There have been several discussion threads around the subject of infinity, sum to infinity and whether 0.99999 recurring = 1.

I think these all miss the point.

There are many branches of mathematics; no one knows them all; they are not all consistent with each other.

What makes a branch of mathematics is a set of consistent axioms and the theorems that can be proved from these.  Let me give an example first of an inconsistent set.

axiom 1.  a + a = b
axiom 2.  a + a = c
axiom 3.     b ≠ c

Straight away you can see these are inconsistent.  Any two are OK.  But add the third and it all goes horribly wrong.

Anyone may make up a new branch of mathematics by stating the axioms.

Others may criticise if they can find an inconsistency or of they find a flaw with a proof but that's the extent of their options.  You don't have to use the theory; you can ignore it.

Now there is a perfectly consistent set of axioms for allowing the concept of infinity into number theory.  With these added, lots of new, and useful things can be done.  (calculus for instance)  Or you can leave infinity out and limit your maths to what can be done without it.  It's a free choice.

You can, if you want, limit yourself to {counting numbers} with + and x.  Plenty of useful things can be done with just these and some people get by for their whole lives with just that.  Or you can add new axioms as you find you need them.   Lots of maths courses leave out complex number theory and you just have to say that some quadratics have no real solution.

So no one has the power to un-invent infinity; as long as one person (**) wants to keep it, that's enough.

** That'll be me.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #36 2012-10-26 22:58:55

noelevans
Member
Registered: 2012-07-20
Posts: 236

### Re: Infinity multiplied by infinity

Yes indeedy!

I agree.  After all math is a language.   We don't have to speak the language if we don't want to.  Or we can use only the parts of the language that we choose.  It all depends on our individual axioms of choice.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).
LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

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## #37 2012-10-26 23:16:19

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

bob bundy wrote:

axiom 1.  a + a = b
axiom 2.  a + a = c
axiom 3.     b ≠ c

I don't wish to be a stick in the mud, but that set of axioms is not incosistent, because you haven't defined + to be either commutative or transitive.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #38 2012-10-26 23:36:47

bob bundy
Registered: 2010-06-20
Posts: 8,354

### Re: Infinity multiplied by infinity

Oh ha ha!

I wasn't advancing it a full theory of anything.

Actually, it's the rules for substitution that are missing.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #39 2012-10-26 23:44:53

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

What substitution?

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #40 2012-10-26 23:48:06

bob bundy
Registered: 2010-06-20
Posts: 8,354

### Re: Infinity multiplied by infinity

a + a = b
a + a = c

a + a = a + a so if you substitute using axioms 1 and 2 you get

b = c which contradicts axiom 3.

You don't need commutativity or transitivity.  I may choose to have them.  But maybe not.  They're my axioms after all.

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #41 2012-10-26 23:50:26

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,606

### Re: Infinity multiplied by infinity

Hi Bob;

I think you see the problem. You defined a system consisting of only 3 axioms and people are already questioning its validity. Imagine mathematics with its thousands of theorems and axioms.

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

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## #42 2012-10-26 23:57:29

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

bobbym wrote:

Hi Bob;

I think you see the problem. You defined a system consisting of only 3 axioms and people are already questioning its validity. Imagine mathematics with its thousands of theorems and axioms.

Quite the opposite. I am questioning its invalidity.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #43 2012-10-27 01:23:16

bob bundy
Registered: 2010-06-20
Posts: 8,354

### Re: Infinity multiplied by infinity

Stefy wrote:

I am questioning its invalidity.

So you think I've made a valid set of axioms. hhhhmmmmm!

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #44 2012-10-27 01:57:06

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

It is neither valid nor invalid. It is incomplete. You haven't defined the relations + and =.

Last edited by anonimnystefy (2012-10-27 01:57:30)

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #45 2012-10-28 11:44:12

Calligar
Member
Registered: 2011-09-24
Posts: 272

### Re: Infinity multiplied by infinity

Hmm, the issue is, I don't think it's impossible to...officially take it out.  There will always be those who use it, and it would likely be remembered throughout history, maybe even added again, but that doesn't mean it can't be officially taken out either.  It is why I argue for its case; I definitely see potential in it if it doesn't already have anything that's really necessary.  But arguably to that point, I'm sure you could argue quite a lot more isn't absolutely necessary, yet without it, math would in turn be much harder.  Infinity is a good idea.  It may provide confusion, especially with all the branches of math using it, some in arguably contradictory ways, but without it, I feel it would do more damage then not.

There are always other variables.  -[unknown]
But Nature flies from the infinite, for the infinite is unending or imperfect, and Nature ever seeks an end.  -Aristotle
Everything makes sense, one only needs to figure out how.  -[unknown]

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## #46 2012-10-28 12:15:45

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

And besides, the systems that differ on whether or not infinity os included differ only by an axiom.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #47 2012-10-29 12:08:38

circlemaker
Member
Registered: 2011-04-03
Posts: 20

### Re: Infinity multiplied by infinity

I've worked with infinity a lot so I'll chime in.  I also take issue with some of the conventional wisdom surrounding ∞ so the following is non-standard.

There are different uses of the term infinity in math.  Perhaps the most common is in reference to transcendental numbers.  Pi for example is an infinite decimal expression, but as a distance it's not ∞.  It exists somewhere between 3 and 4.  Pi is a finite distance from 0 (even if we can't quite pin down the exact distance).

When I refer to ∞ I mean the farthest possible distance from 0.

0 is the lower limit, ∞ is the upper limit. (think radial or scalar dimension)

0 * 0 = 0 (can't get any smaller)
∞ * ∞ = ∞ (can't get any larger)

Like 0, ∞ is non-polar.  +∞ and -∞ are the same thing.  If there is a way for +∞ and -∞ to be distinct, there also must be a way for +0 and -0 to be distinct (which there might well be but I'm not willing to get into that much detail just yet).

As measured from 0 to the tangent, ∞/∞ = 0 ± 1.  Details here, because words alone don't do it justice: [ http://www.perspectiveinfinity.com/root_grid.html#infdivinf ]
0 * ∞ offers a similar result but exists 90 degrees from ∞/∞ on the unit circle.  All points on the unit circle can be understood as distinct fractional representations of ±1.

In addition to 0 ± 1, ∞/∞ also = 0 ± every other natural number.  From an xy perspective when tangent is parallel with the x axis, ∞/∞ results in the entire y-axis.  Only by measuring to specific tangents can we limit the result, such as is the case with 0 ± 1.

0 is an origin.  When we count from 0, everything is relative to 0.  We don't preface every number with 0+ or 0-, even though that's exactly what we're doing.  ∞ can also be used as an origin.  Now instead of counting from 0 towards ∞ we can count from ∞ towards 0.  ∞ + 1 is a finite distance from ∞, but as far as 0 is concerned ∞ + 1 = ∞.  Different perspectives, different answers.

I refer to ∞ along with numbers relative to ∞ as "shadow numbers" since ∞ is not considered a "real number".

Also:
∞ + ∞ = ∞
∞ - ∞ = ∞
Remember, non-polar!  Like zero, infinity is timeless, non-dualistic.  Try splitting something timeless into finite parts and all we split is our perception of it.

Nothing is undefined.

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## #48 2012-10-29 13:34:36

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,037

### Re: Infinity multiplied by infinity

infinity-infinity is not infinity. It is undefined.

I do not understand what you mean by infinity/infinity=0+/-every other number...

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #49 2012-10-29 19:34:53

Mpmath
Member
Registered: 2012-10-11
Posts: 216

### Re: Infinity multiplied by infinity

I agree with anonimnystefy, infinity-infinity is undefined.

Winter is coming.

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## #50 2012-10-29 21:29:31

Mpmath
Member
Registered: 2012-10-11
Posts: 216

### Re: Infinity multiplied by infinity

And also infinity divided by infinity = undefined.

Winter is coming.

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