Covering Sphere w/ Disks: Min Required Radius k

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Discussion Overview

The discussion revolves around the problem of determining the minimum number of disks required to perfectly cover a sphere, specifically when the radius of the sphere is k times the radius of the disks. The scope includes mathematical reasoning and theoretical exploration related to geometric covering problems.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant questions the interpretation of the problem by clarifying that it involves a "sphere" rather than a "ball."
  • Another participant references the disk covering problem in relation to spheres and suggests considering the number of steradians needed for coverage.
  • A participant calculates that, based on the surface area of a sphere and the area of a disk, four disks would be sufficient under the assumption that the disks can be manipulated without changing their area.
  • A different participant agrees with the conclusion of needing four disks for equal radius cases but proposes that when the sphere's radius is k times that of the disks, the number required would be 2k², while expressing skepticism about the feasibility of four disks covering a sphere without distortion.

Areas of Agreement / Disagreement

Participants express differing views on the minimum number of disks required, with some calculations suggesting four disks while others propose a formula involving k. The discussion remains unresolved with competing models and interpretations.

Contextual Notes

Assumptions regarding the manipulation of disks and the definitions of coverage are not fully explored, leading to potential limitations in the conclusions drawn.

Ynaught?
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What is the minimum number of disks required to perfectly cover a sphere with a radius k number of times the radius of the disks?
 
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Werg22, he said "sphere", not "ball".
 
Thanks Wergs22 and HallsofIvy,

...but I was looking for a solution more akin to the disk covering problem http://mathworld.wolfram.com/DiskCoveringProblem.html" but for a sphere rather than the complex plane extended over a sphere. Maybe if we consider the number of steradian needed to cover a sphere?

As an aside, the Riemann Sphere brings up another question... Is there a 3 dimensional complex space where the traditional complex plane has an orthogonal counterpart sharing the same Real axis?
 
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Since the Surface area of a sphere is 4*pi*r^2 and the area of a disc is pi*r^2 wouldn't you need just 4? This is assuming of course you could manipulate the shape of the discs without changing their area.
 
Hey Diffy, I came to the same conclusion for the case where the radius of the sphere and the radius of the disks are equal. And when the radius of the sphere is k times the radius of the disks the number is 2k^2. But I can't see how four disks can cover a sphere without being distorted, in which case, the disks are no longer disks...
 

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