Sunday, July 22, 2012 6:54:28 PM
@MacGuffin: I have written software that allows one to visualise true 4-d objects in 3-d using 3-d glasses. I have spent a good amount of time over the last 30 years working on it, and I have gained a solid understanding of 4-d geometry in the process.
Well, if you can *buy* 3D projections of the real thing on the internet and everything, that *must* prove that the 4D object that said 3D projection is a projection of can`t exist.
Read this, then realise how mistaken you are. To quote:
"While the Möbius strip can be embedded in three-dimensional Euclidean space R3, the Klein bottle cannot. It can be embedded in R4, however."
As I said, this *is* a 3D projection of such an embedding in R4 - that`s how the object is shown to pass through itself. That only happens in 4D.
Saturday, July 21, 2012 1:26:05 PM
@MacGuffin--a 4-d Klein Surface would not show an intersection and would rotate without any flattening.
This is a matter of some expertise for me. Again, this is a *3D projection* of a 4D Klein Bottle. Nobody is saying that it is the 4D object itself. If it was, we'd be unable to perceive it, since we live in 3D.
I guess it`s not that much of an area of expertise for you, or you`d be able to understand that simple concept.
Saturday, July 21, 2012 4:17:13 AM
@MacGuffin: I don't know why you keep insisting that Klein bottles are 4D objects when they are clearly NOT.
Seriously, no part of a Klein bottle needs to project into the 4th dimension for it to be a Klein bottle, therefore it is, by definition, *not* a 4D object.