Intersection of a 4D line and a 3D polyhedron in 4D

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Discussion Overview

The discussion revolves around the intersection of a 4D line segment and a 3D polyhedron in 4D space. Participants explore the nature of this intersection, questioning whether it results in a point and seeking mathematical proof for their observations.

Discussion Character

  • Exploratory, Technical explanation, Conceptual clarification

Main Points Raised

  • One participant questions whether the intersection of a 4D line segment and a 3D polyhedron is a point in 4D if they intersect, expressing uncertainty about how to prove this.
  • Another participant suggests that if the line and polyhedron are not in the same 3D space, the intersection will indeed be a point, even when considering a full 3D volume and a full line.
  • A participant requests a mathematical proof or hint for the observation regarding the intersection.
  • One participant describes a method to approach the proof, comparing it to the intersection of a line and a plane in 3D, indicating that the concept extends with an additional coordinate.

Areas of Agreement / Disagreement

Participants express differing levels of certainty regarding the nature of the intersection, with some proposing that it is a point under certain conditions, while others seek clarification and proof, indicating that the discussion remains unresolved.

Contextual Notes

The discussion may be limited by assumptions about the alignment of the 3D polyhedron and the 4D line segment, as well as the definitions of intersection in higher dimensions.

LCDF
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Is the intersection of a 4D line segment and a 3D polyhedron in 4D a point in 4D, if they at all intersect? Intuitively, it looks like so. But I am not sure about it and how to prove it.
 
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If they are not in the same 3D space then the intersection will be a point. You can even use the full 3 D volume and a full line and it will still be a single point.

You can look at the line segment in a coordinate system where the 3D object is aligned with three axes, for example.
 
Thanks. Is there a mathematical proof for your observation? A hint would also work.
 
My second paragraph is a description how to get to a proof.

It's basically the same as with a plane and a line in 3D, just with one more coordinate.
 
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