Some theories similar to String and Super String Theory speak of the possibility of many, many alternate dimensions. I see no reason why ex-l’s theory could not be a possibility, but to look at it from a different perspective, perhaps humans are capable of creating their own dimensions with the power of consciousness. A dimension which is real in an abstract form, and could be overlaid on physical reality or be the size of an atom. A real dimension noneth the less, at least in an abstract way which could be called someone’s aura, a part or an extension of it.
I had an experience at Madubhan at a morning Bhog offering where I was doing my little fly up to the Subtle Regions while the trance messenger on stage did as well. I got my experience-message and when the lights went on and the trance messenger gave the message I was very moved to hear her speak of things that I had also just experienced in my Subtle Region tour. The details elude my memory, it was the astonishment of what happen which I vividly remember as tears welled up in my eyes from the impact of the experience. It could very well be that we all collectively created the experience and thus experience it in the abstract form or that the dimension really exist and thrives by the faith and mental activity of others. Many other possible explanations as well of course.
I sometimes think all the different concepts of the astral plane, Subtle Region included, are part of one big abstract dimension which is only as real as thoughts are real. A dimension where people can go and make their own little house, temple, safe place, dimension or experience a dimension already created by someone else. Something like a dimension which consists of mental and emotional energy, but of course there could be many and not just one.