4D portal

[Andrewc]

If someone jammed a 4D cylinder into our world, it would look like a sphere floating in space right? If you jammed a nail into a 2D world, then extracted it, would it leave a rip in the 2D world in which 2D creatures could fall? If the 4D cylinder was extracted from our world, would it leave a spherical rip in which we could "fall" a 4D direction?

I guess the biggest assumption here is that there is some kind of "fabric" that could be ripped. Is this at all conceivable? What are some other problems with this idea?

Thanks.

[Nick]

Other than that you would have to fit in the hole, it makes sense to me. But that would suck to fall through.

There is already a thread about whether or not the 2D world could be "touched" by the 3D world, but I can't seem to find it anywhere...

[bo198214]

The question does not so much depend 4D/3D. So consider a paper as approximating a 2d world. The inhabitants can only move to points where the paper substrate is.

If you cut out a disc there then the inhabitants simply can no more move to points where the disc was and if someone was in this disc during cutting then he afterwards is in a circular jail.

However it is not the experience of our 3d world that space can stop somewhere (at a sphere in this example), i.e. that you would bump directly into an infinitely hard border somewhere. Our experience is that however far we go, we can still go a step farther.

This could also achieved in this case if we chose the geometry such that there is an infinite way to the boundary of the sphere/disc, i.e. that the remaining space is topologically open. Perhaps ask Wendy about it, it is to cumbersome to explain in more detail in the moment for me.

A 2d being needs some substrate to live in: a 2d world. For me it makes no sense for a 2d being falling into a 3d world. However you can cut and bend the 2d world and afterwards they live in the deformed 2d world.
Though this is anyway hypothetical as nobody ever encountered a real 2d world yet.

There is already a thread about whether or not the 2D world could be "touched" by the 3D world, but I can't seem to find it anywhere...

Probably, because Keiji deleted the search words.
See thread Recent downtime

[Nick]

Actually, I manually searched for it.

[Andrewc]

Actually, I ask this question because I'm something of a writer and I want to make sure my idea has some logical grounding that I can jump off of--I mean, its sci-fi/fantasy stuff, but it should still be somewhat believable.

Although I have a lot of imagination, my brain is extremely logically inept.

If anyone who is a logical thinker wants to read my chapter where the characters explain this phenomenon and give me a critique, I would be most grateful. It's less than 5,000 words and I think any fantasy/sci-fi fan would find it at least a little bit interesting.

Anyone...?