@Roby “in short…NOTHING”
That’s the point…
This sounds crazy to those who don’t study linguistics. “NOTHING” = NO+THING.
Materialists consider “THING“s, as physical objects which abide by rules of the physical universe. Thus, no+thing is a lack of physicality altogether. Concepts of “short” and “the other side” do not apply. It’s like asking what’s North of the North Pole. No+Thing.
Now the Immaterialist expands the concept of what a “Thing” can be. Emotions and Thoughts can be things which lack materialism and therefor are not bound by rules of physicality. To one who considers thought to be a simple assemblage of neurochemicals, this is unacceptable. But to one who understands thought as separate from the neurochemicals which represent them in physicality, it makes perfect sense.
This “flatness” of the known universe is literally a “plane of existence”. Like a silicon wafer in a computer, where information is pushed around amongst hurdles of entropic distortion. But the flat wafer is only a physical representation of the thoughts of whom designed it.