Originally posted by PhilHe's explained it pretty in depth actually. Morrison views the fifth dimension as pure imagination. ie. any time we, in the real world, imagine something(however big or small), we are actually accessing the fifth dimension in some way. And before you ask: yes, Morrison has flat-out stated his perception that 'imagination=the fifth dimension' stems from multiple LSD trips he had decades ago, lol.
Maaaybe.I'm curios how Morrison would explain it.
He's also made his opinion on the matter clear over the years, on panel:
http://i.imgur.com/xZTNfFJ.jpg
"Imagination is the Fifth dimension."
And very recently(though not under Morrison, but certainly written in the same hue), Mxy had a page-long dialogue explaining his existence as an imagination-based thought-form:
http://i.imgur.com/eR9BixR.jpg
"I don't need a body. I've lived on, and will live on, in heads. The heads of the authors who write me. I have no vocal cords, and yet right now, you're hearing my voice. I'm living in your head right now [...] Ideas are agency. We are Gods. You are just puppets. As long as there's one of you, there'll be a hundred of us."
*There's quite a bit more, but no real need to post it here(and I'm sure you've seen the material anyway.)
In a nutshell: when you factor in Morrison's perception of the fifth dimension, there's no real way to list/place it on a 2D plane, as it is not really a distinct physical location -- it exists primarily in the minds/imaginations of the readers. That's why I believe it transcends his Map all together. /shrug
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On another note, Phil: have you ever read Morrison's "Supergods" novel? If you want some fantastic insight as to how that man perceives concepts like this, it's a must read... Really expands on his metatextual works. 👆