If Flatland's Model Is Correct...

Visualizing the First ' Second ' Third ' and (hinting at) the Forth dimensions, Flatland (story) describes an existence, where, all the dimensions interact with each other (however limited). If this expression is believed, then, would it be too farfetched to imagine the 3Dness in the universe is the 4th dimension seeping into our 3D "plane" ?

Would it be soo difficult to imagine a galaxy or nebula as, simply, the fragments of a 4D thing "bleeding" through ?

The theory would be, the cluster of things we see, in space, is, actually, part of a larger thing we CAN'T see... And, only, bits of it can penetrate the 3rd dimension, but, because it's one thing, it has to stay together, like a nebula or galaxy. 

Maybe the galaxies ' nebulas ' rogue objects are, even, all, 4D biological cells (???)

What The Forth Dimension SHOULD Be

There's a possibility the forth dimension is visible AND interactable. The celestial bodies (CBs) may be the evidence of the forth dimension seeping through. If Flatland has any validity, then, what we're seeing and interacting with may be the bits that the third dimension can comprehend - leaving all those gaps between CBs probs is the forth dimension incomprehensible by the third dimension.

Imagine the Human body; all the cells inside wouldn't comprehend the situations of Human society, but they function and interact with all the smaller details of the body. The smaller details are the only things of Humans the cells understand.