Understanding Pi: its Role in Symmetry and How it Was Found

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Discussion Overview

The discussion centers around the mathematical constant pi (π), its significance in symmetry, its value, and its historical discovery. Participants explore its role in various geometric formulas and the implications of its definition, touching on concepts from geometry, calculus, and philosophical interpretations of mathematics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants assert that pi is fundamental in formulas related to symmetry, such as those for circles and spheres.
  • One participant claims that the value of pi is not 22/7, but merely an approximation.
  • Another participant suggests that pi can be understood as the convergence of series derived from integrals.
  • Several participants emphasize that pi is defined as the ratio of the circumference of a circle to its diameter.
  • Some argue that the definition of pi in modern analysis is a result of integration, rather than a foundational definition.
  • There is a discussion about the historical understanding of pi, with references to its recognition long before calculus was developed.
  • One participant introduces the idea that the definition of unit area could vary based on different cultural interpretations, suggesting a relativistic view of mathematical constants.
  • Another participant references historical figures like Euclid and Descartes to discuss the philosophical implications of mathematical concepts and their definitions.
  • Some express skepticism about the notion that modern analysis redefines all prior mathematical knowledge.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the definitions and interpretations of pi. While some agree on its mathematical properties, others contest the implications of its definition and historical context, leading to multiple competing views.

Contextual Notes

Participants mention various mathematical concepts and historical interpretations that may not be universally accepted or defined, indicating a reliance on specific definitions and assumptions that could vary among different mathematical frameworks.

  • #61
HallsofIvy said:
I disagree with "it originally came about in desire to find the area of a circle". I think there is clear historical evidence that \pi was first used to find the circumference of a circle. Yes, one can easily write that "c= 2\pi r" using [it ex]2\pi[/itex], but if you are talking about a pillar or tree trunk, it is far easier to measure the diameter rather than the radius. That's why 'c= \pi d" is much more natural.

Timber cruisers in the woods of the Pacific Northwest use a tape measure marked in Pi units to measure the diameter of a tree. Just wrap the tape around the tree and read the diameter. At least they were used when there was a active logging industry.
 
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  • #62
ObsessiveMathsFreak said:
Why on Earth would anyone wish to do such a thing? What possible purpose or reason is there in denying at the outset what pi actually is?

It's simply not correct to come up with a formula or series that gives pi and take that as the definition, and later simply point out that the number also happens to be the ratio of the circumference to the diameter. That would be akin to coming up with a formula or series for Plank's constant or the magnetic permeability of a vacuum and declaring it as the definition for these constants.

Pi is the ratio of the circumference of a circle to its diameter. That's what it is. Millennia from now when no one is doing integration, or series or working in base ten, or using fractions, or just about anything we do now, pi will still be there as the ratio of circumferences to diameters. No number system, no analysis, no axioms, no definitions, nothing.

That's what pi is. How we find, measure or approximate it is entirely up to us, but the definition is quite out of our hands. You may be uncomfortable with this, but the universe does care about any philosophical objections you might have. It just is. Like pi.

The circle is not a physical entity, it's a mathematical one. The circle does not exist in nature for the simple reason that it is not applicable.
 
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  • #63
Werg22 said:
The circle is not a physical entity, it's a mathematical one. The circle does not exist in nature for the simple reason that it is not applicable.

nonsense, mankind has been making wheels for thousands of years. We have been making "perfect circles" , that is circles within our ability to measure, for thousands of years.

Whether or not a perfect circle exists is irrelevant.
 
  • #64
A ten year old might qualify a wheel a circle, I do not.
 
  • #65
That is your problem not mine.

Thread done.
 

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