Somebody is living on a spherical world

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Discussion Overview

The discussion revolves around a hypothetical scenario involving a person drawing a circle of radius 1m on a spherical world using a rope. Participants explore the implications of this scenario, particularly focusing on the constraints of the rope and the concept of "two possible worlds." The discussion includes theoretical considerations and interpretations of the problem's parameters.

Discussion Character

  • Exploratory, Conceptual clarification, Debate/contested

Main Points Raised

  • Some participants question the clarity of the problem, noting it lacks sufficient information to define a specific answer.
  • One participant suggests that the problem implies an infinite number of worlds where the circumference exceeds 1m, indicating ambiguity in the scenario.
  • Another participant interprets the problem as involving the use of the rope as a compass to draw circles on a sphere, proposing two methods: one involving a great circle and another involving a straight line inside the sphere.
  • There is a suggestion that for a given length of rope, there may be a unique radius of the sphere that allows both drawn circles to have the same radius of 1m.

Areas of Agreement / Disagreement

Participants express differing views on the interpretation of the problem and its implications. There is no consensus on the specifics of the two possible worlds or the conditions under which the circle can be drawn.

Contextual Notes

The discussion highlights limitations in the problem's formulation, particularly regarding the definitions of the "two possible worlds" and the assumptions about the rope's constraints.

kleinwolf
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Somebody is living on a spherical world. He is drawing a circle of radius 1m with a rope. We know there are only 2 possible worlds.

What is the radius of this world knowing the rope cannot circumvent the sphere ?
 
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kleinwolf said:
What is the radius of this world knowing the rope cannot circumvent the sphere ?

which world are you exactly talking about.

and can you please elaborate on the 2 worlds.
 
The problem has insufficient information with which to define an answer.

Well, except for a meta-answer, as in: any of an infinite number of worlds whose circumference is > 1m.
 
Yes you're right : the guy tells us the perimeter of that circle of 1m radius. We know this and the fact (by another source of information) that there are only two possible worlds.
 
I think I might know what kleinwolf means, but I am too lazy right now to get the answer. Here is a possible meaning to the puzzle:

First of all, I think he means to use the rope as a kind of compass, as you might use to draw a circle on a flat piece of paper. There are two ways to do this on a sphere without breaking through the sphere. One is to stretch the rope taut around a great circle of the sphere. The other is to stretch the rope straight on the inside of the sphere. I assume (because the problem is probably solvable), that for a given length of rope, there is only one radius for the sphere that allows these two drawn circles to have the same radius. Thus, there is only one radius for the sphere that would allow the radii of the circles to be 1m.
 
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