Is Distance Between Positions in Infinite Space Always Finite?

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Discussion Overview

The discussion revolves around the question of whether the distance between any two positions in infinite space is always finite. Participants explore various interpretations of "infinite space," including mathematical and physical perspectives, and consider implications for travel between points in such spaces.

Discussion Character

  • Exploratory
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants emphasize the need to define "position" and "infinite space" clearly, suggesting that in finite dimensions with finite coordinates, distances are finite.
  • Others question whether there are points in an infinitely large universe that cannot be reached in finite time, raising concerns about the implications of the universe's expansion.
  • A participant introduces the concept of mathematical spaces where points can be infinitely far apart, using disconnected components in ##\mathbb{R}^2## as an example.
  • Some participants argue that while distances between any two identifiable points are finite, there is no upper limit to the distances that can exist between pairs of points.
  • A thought experiment involving infinitely many mathematicians traveling from a starting point to various destinations is discussed, with participants debating whether there will always be mathematicians still traveling and what that implies about their journeys.
  • There is a discussion about the nature of metrics and how distances are defined mathematically, with some asserting that all mathematicians will reach their destinations in finite time despite the existence of an infinite set of travelers.
  • Some participants express confusion about the relationship between the travel times of individual mathematicians and the overall scenario involving infinite distances.

Areas of Agreement / Disagreement

Participants do not reach a consensus on whether the existence of an infinite number of mathematicians traveling implies that some will never reach their destinations. There are competing views on the implications of infinite distances and the nature of travel in infinite space.

Contextual Notes

Participants highlight the distinction between finite distances and the concept of unbounded distances, noting that while individual travel times are finite, the distances involved can be arbitrarily large.

  • #31
netzweltler said:
step 1: at t = 0 I am shifting the line [0, 1] to position [-0.5, 0.5]
step 2: at t = 0.5 I am shifting the line at [-0.5, 0.5] to position [-0.75, 0.25]
step 3: at t = 0.75 I am shifting the line at [-0.75, 0.25] to position [-0.875, 0.125]
...

All shifting is done before t = 1. No action is done at t = 1. Countable infinity doesn't allow a last shift at t = 1, which clearly is needed for point -1 to be covered.

...what? Where does "countable infinity" enter into all of this? And what does it have to do with "moving at t=1"? You aren't even bothering to explain what it is that you're doing or asking, and it's making it very difficult to answer any of your questions. What does this have to do with "positions in infinite space"?
 

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