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I am trying to find a story I read as a child. I remember little about it except for the following:
I suspect I read it before 1985, but it was a school library book which means it could be God knows how much older than that.
This may mean it was a book meant for younger readers.
In memory it "feels" longer than a short story, but I was a bit young to be reading novels. If I had to guess, I would guess novella length or shorter.
English language, available in the United States.
Contains several descriptions and ideas that stuck with me:
The overall idea was that there were "parallel" worlds, parallel like the pages of a book, except for one that was (for whatever reason) skew to the rest, or warped somehow, and therefore intersecting the rest
Geometry between that world and the rest seemed fundamentally incompatible as a result
The most evocative example of this (by definition, since it is the only one I recall with clarity) is a description of... something... as looking like "Two concentric circles, intersecting in three places." This is obviously gibberish (concentric circles intersect nowhere unless they also have the same radius in which case they overlap perfectly; non-concentric circles that do intersect do so only at two points) but I was just old enough to realize it was gibberish being used to a purpose. It stuck with me.