Is 0/0 the Key to Understanding Infinity?

  • Context: Graduate 
  • Thread starter Thread starter cdux
  • Start date Start date
  • Tags Tags
    Infinity
Click For Summary

Discussion Overview

The discussion revolves around the mathematical expression 0/0 and its implications, particularly in relation to concepts of indeterminacy and undefined values. Participants explore various interpretations and the philosophical implications of this expression within mathematics.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Exploratory

Main Points Raised

  • Some participants propose that if both numbers approach 0, the result could be anything from -∞ to +∞, suggesting that 0/0 could represent "everything."
  • Others argue that 0/0 is undefined and does not have a unique value, emphasizing that it is an indeterminate form.
  • A participant describes 0/0 as a "cloud of numbers around 1," raising questions about potential quantum mechanical implications.
  • Another viewpoint asserts that the expression 0/0 lacks meaning and is merely a combination of symbols without inherent value.
  • Some participants highlight the importance of formal definitions in mathematics, cautioning against interpreting mathematical symbols as having "real" existence.
  • There are discussions about the nature of mathematical reasoning, with some participants expressing frustration over perceived sarcasm in responses and the tone of the discussion.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the interpretation of 0/0. While some agree on its indeterminate nature, others maintain that it can imply a range of values, leading to ongoing debate.

Contextual Notes

Limitations in the discussion include varying interpretations of mathematical terms like "undefined" and "indeterminate," as well as differing philosophical approaches to the meaning of mathematical expressions.

  • #31
cdux said:
Both approach towards zero so they will both tend to be two very small numbers. This points to a similarity. They are not arbitrary, they are specifically very small. Hence it comes to reason that while the result can be anything between -∞ and +∞, they will have a bias towards 1 rather than ∞.

If you're happy to avoid any Mathematical rigour and just throw ideas out there, then I'll have my take on it too.

I could also argue that since both numbers are tending to 0, and "many" indeterminate forms of 0/0 are far from 1, being either \pm\infty then this is evidence that points towards it having a bias towards infinity rather than 1. I'm imagining that the only reason you're seeing a bias towards 1 is because x/x=1 for every other real value of x. Or, how about we take another approach? If we consider the limits that are non-negative, then the value for 0/0 must be [0,\infty) and since if we consider

\lim_{(a,b)\to 0}\frac{a}{b}

then the value is only equal to 1 when a approaches 0 at the same rate as b, so there are going to be equally many values of a that approach zero faster than b (giving a value of < 1) as there are going to be values of a approaching 0 slower than b (giving a value > 1), so does this mean 1 is equidistant between 0 and \infty?

*** There is of course no mathematical rigour in these statement I've made, and I absolutely do not stand by them.
 
Physics news on Phys.org
  • #32
cdux said:
Is it not possible to produce a fuzzy output?
No, and you have been told this repeatedly. Division, when it is defined, produces a single result. Furthermore, division by zero is undefined.
cdux said:
My understanding is that a/b with them independently approaching zero, will produce a fuzzy 'anything' number around 1.
Then your understanding is flawed.
These three limits are all of the [0/0] indeterminate form, but the limit values are wildly different.
$$\lim_{x \to 0} \frac{x}{x^2} \text{does not exist} $$
$$\lim_{x \to 0} \frac{x^2}{x} = 0$$
$$\lim_{x \to 0} \frac{x}{x} = 1$$

What you seem to be missing is that even though both numerator and denominator are approaching zero, how quickly one or the other is approaching zero is the determining factor.
cdux said:
PS. If they are equal it will produce 1.
If they both approach zero at the same rate, the limit will be zero.


cdux said:
A weird postulation this may produce is that if that 'anything' has a tendency to be closer to 1 rather that infinities then it might point towards why physical numbers tend to not be infinite.
Nonsense.

cdux said:
Both approach towards zero so they will both tend to be two very small numbers.
Yes, of course. That's what "approaching zero" means, but again, what's important is how quickly one or the other (or both) are approaching zero.
cdux said:
This points to a similarity. They are not arbitrary, they are specifically very small. Hence it comes to reason that while the result can be anything between -∞ and +∞, they will have a bias towards 1 rather than ∞.
No.
cdux said:
The same would be true for ∞/∞.
No, absolutely not, and for the same reason I gave above. The important consideration is not that both numbers are getting arbitrarily large, but rather, how quickly one or the other (or both) is getting large.
 
  • #33
cdux said:
Both approach towards zero so they will both tend to be two very small numbers. This points to a similarity. They are not arbitrary, they are specifically very small. Hence it comes to reason that while the result can be anything between -∞ and +∞, they will have a bias towards 1 rather than ∞.

Here is one specific and very important (it's the basis for all calculus, and it's been known and well understood since the 17th century) example:\lim_{a\to0}\frac{f(x+a)-f(x)}{a}

It should be clear that both the numerator and the denominator are approaching zero. However, the value of this expression doesn't have a "bias towards 1" - it is the slope of the graph of ##f## at the point ##x## (the ##a## disappears everywhere when you take the limit) and it's only going to have a "bias towards 1" if ##f## is specifically the function ##f(x)=x##. Trivially, it has the value ##A## when ##f## is the function ##f(x)=Ax## and there's no reason why ##A## should be anywhere near one. It gets even more interesting and even less biased towards one if ##f## is a more interesting function (try it with ##f(x)=2x^2## as an exercise).

As I said, this application of the ##0/0## machinery was discovered along with differential calculus in the 17th century. Until you've worked through it, you're restricting your mathematical understanding to the state of the art - four centuries ago.
 
Last edited:
  • Like
Likes   Reactions: 1 person
  • #34
I think it's time to close this. Many posters have given clear and correct answers. It's up to the OP to decide whether he wants to listen or not.
 

Similar threads

  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 1 ·
Replies
1
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 17 ·
Replies
17
Views
6K
  • · Replies 6 ·
Replies
6
Views
2K
  • · Replies 14 ·
Replies
14
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
3K