Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!lll-winken!uunet!ncrlnk!ncrcae!hubcap!eos!eugene
From: eos!eugene@eos.arc.nasa.gov (Eugene Miya)
Newsgroups: comp.parallel
Subject: Re: Seeing 4 dimensions experiment?
Message-ID: <5055@hubcap.clemson.edu>
Date: 10 Apr 89 17:41:06 GMT
Sender: fpst@hubcap.clemson.edu
Lines: 50
Approved: parallel@hubcap.clemson.edu

In article <5050@hubcap.clemson.edu> cam@edai.edinburgh.ac.uk (Chris Malcolm) writes:
>I have heard a rumour that someone implemented a 4-dimensional
>modelling system, which permitted the construction of 4D solids, and
							  ^^^^^^
That is a 3-D term.  If true this could be interesting, but I don't
think it would involve much at this time.  You have to be skeptical.

>viewing them (2D projections) on a video screen, on sufficienlty fast
>machinery that users could use joysticks or whatever to navigate around
>(shift the point of view as though moving) in a 4D world. The story
>goes that about half of the people subjected to this exploratory
>experience would exclaim, after less than an hour, "I see it! I can see
>4 dimensions!"

Half is not necessarily statistically significant.  We already live in a
4-D universe.

>This would be very interesting if it were true - e.g., it would suggest
>that the brain is not built to "see" 3 dimensions, but simply (why do I
>keep using that word!) to make sense of n dimensional spaces, and 3
>happens to fit nicely onto the navigable world.
>
>Can anyone supply references, pointers, corroboration or debunking?

It is argueable whether or not we can perceive 3 physical dimensions.
CRTs and retinas are 2-D.  What makes 3-D is the human brain working
with two eyes, and the structure of the eye itself.  Cartographers
have worked centuries on the problem of projecting a 3-D globe onto
a 2-D service.  Mathematicians have worked decades to generalize on this.
Simply "seeing" this is harder to believe than room-temperature fusion. ;)
See, the people working in computer animation have produced some relatively
slick animations flying thru terrain.  The problem is these videos are
useless as maps as people use maps.  They can't tell you how far London
is to New York, or Los Angeles to San Francisco.  They don't incorporate
multiple levels of information which appear on maps as they exist today.
They are strictly geometric and temporally fixed in most cases as well.
There are probably interesting mathematical techniques for thinking
about it, but I don't have them right here (perhaps more appropriate for
comp.graphics or sci.math).  I am working on a 4-D system for relativistic
efforts with a friend (on spare time).

So I would be interested in references or other pointers, but
I can't debunk without more information.  So be skeptical.

Another gross generalization from

--eugene miya, NASA Ames Research Center, eugene@aurora.arc.nasa.gov
  resident cynic at the Rock of Ages Home for Retired Hackers:
  "Mailers?! HA!", "If my mail does not reach you, please accept my apology."
  				Live free or die.