Re: OT hypercube (was: Con-other)

Heinlein's... story... makes me... woozy... Although I've been sort of
enlightened on the workings of tesseracts for now (but still have trouble
visualising them). I understood your example, at least.
Though now I have a new question -- what happens when, on a plane, two 2D
objects travelling in intersecting directions meet? Do they bump? Overlap?
Pass right through?

Eugene

On Sat, May 31, 2008 at 11:22 PM, Mark J. Reed <markjreed@...> wrote:

> On Sat, May 31, 2008 at 10:57 AM, Eugene Oh <un.doing@...> wrote:
> > Planar rotation goes even further off my radar. I can't even begin to
> > imagine it! I envy all you people who grasp mathematics so easily. :(
>
> Well, grasping the math is one thing.  I still can't visualize this
> stuff.  But these days you can  play with computer models in real-time
> - "rotate this 30 degrees cata"... and sort of get a feel for how it
> fits together, although I find that feel doesn't last long afterward.
>
> Squares rotate around points.
> Cubes rotate around axes.
> Tesseracts rotate around planes.
> Penteracts rotate around spaces.... that's where it gets weird for me.
>  Our entire universe is an axis of rotation for these things. :)
>
> > There is a process of pattern-repetition that has a name either very
> similar
> > or identical to "tesseract", but I can't remember what...
>
> tesselate.
>
> > In 3D terms, that might be like... having a cube that was actually a
> > tesseract but no one realises it because from whichever angle human eyes
> can
> > only see a cube? Is that it?
>
> Sort of. It's like we're 2-d critters walking around inside a plane,
> unable to perceive the thickness of the plane itself.
>
> Your description is closer to the 2d critters' view of intersecting 3d
> critters in _Flatland_.  Or our view of the titular structure in in
> the Heinlein story "And he built a crooked house", where each room was
> a cube of a tesseract.
>
> Imagine that you are a 2d critter walking around the surface of a
> cube.  The angle change at the directions is completely invisible to
> you, so all you see is six square rooms, four in a line N-S, with one
> east and one west of the second-to-southernmost room.  Perfectly
> normal-looking, but they have magic doors!  If you stand in the south
> room facing south and look through its southern door, you find
> yourself looking into the north room from its north door - wraparound!
>  Which is spooky enough.  But if you stand in the north room looking
> east through its eastern door, you find yourself looking into the
> eastern side room - facing WEST!
>
> --
> Mark J. Reed <markjreed@...>
>

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