Here's what my friend said in reply to what I said about falling through empty space while sitting.:
"I recognise the meditation experiences you're talking about - there's even a name for it in Sanskrit. It's supposed to just be a loosening of the normally rigid connexion between senses and perception - which can in itself be scary enough! Just shrug your mind's shoulders and sit on."
Gosh. I never made much distinction between senses and perception, so I'm not sure what this means, quite. Yet, I can see that perception is something that includes sensory inputs but is also something sort of distinct -- largely because of the relation of intentionality (as the phenomenologists call it). Which is to say that perception involves directed awareness, not just the senses, per se, naked and raw.
Anyhoo, there's a whole lotta shaking going on, as the song goes. Had a lovely mindfulness while eating breakfast experience with my Sweetie, this morning. It arose as naturally as breathing. But I did note that if I really give myself to each bite of food, well, it doubles or tripples in tastyness!