Hi there,
Anon Anon:
--no overt attempt at vipassana (my experience is always broken up into vibrations without trying)
As long as your samatha is strong enough to keep the jhana stable but unstable enough to allow "vipassanation" of your experience, then you're on the right track. I mention this only because, in my past experience, I did have to be "overt" with my intention to vipassanize while heading toward NS (but this could just be idiosyncratic or irrelevant in another way).
Anon Anon:
There is something that occurs sometimes after jhana 8 which I think may be NS. The one time I observed it clearly, it was as if the entire phenomenal world fell away in a fraction of a second, albeit in an extremely low-key, non-impressive, unremarkable way. This "falling away" is unlike the way that cessation is entered upon when attained through vipassana. Then the phenomenal world re-arose (didn't observe how), then the thought "hmm, what was that?" arose, then I felt quite relaxed and positive, unable to continue with more jhana (mind felt uncollected), and reviewed that string of events from memory because I was not observing what lead up to those events and what they were like moment-to-moment as they occured.
Your description reminds me of the first time I attained NS.
Anon Anon:
Other times when I have tried to attain NS there comes a moment where the same aftereffects occured, but the experience that lead up to is was completely unclear. For example, meditating before sleep one night while somewhat tired, I went from jhana 1 to 8, hung out, nothing happened, went through the PL jhanas, back down to 8, then suddenly found myself in a happy / relaxed / tired state where I was content to lay in bed and not think or concentrate for about 30 minutes. Other times it's even more indistinct---I lay in bed before sleep, resolve to attain NS, float around between jhana and sleepiness for awhile, don't pay attention to the progression of jhanas, and then find myself in the same state without a good memory of what came before.
I remember experiences fitting these descriptions as well. I did not consider an event to have been NS unless I was sure that's what happened, though. I did so to hold myself at a relatively high standard so as to ensure mastery rather than settling for an experience that was "maybe, maybe not." I found the memory loss aspect of these experiences to be less pronounced if I was sitting upright, rather than laying down. I theorized that, by laying down, early sleep was beginning to creep in; which usually means short-term memory disturbances. This may be entirely normal for any attainment of NS though, which is why I think that NS is possibly an intentional, direct accessing of deep sleep (or something very similar). Again, tis only conjecture.
Anon Anon:
1) Is the entrance always clear, either at the time or in retrospect?
2) Is the entrance psychologically remarkable or unremarkable? (I expected it to be remarkable, e.g. I expected to think "wow, that was wild!" upon reviewing it, because its description seems quite impressive, but it's no more remarkable than cessation...which I also expected to be remarkable, but which never was. Hmm, a trend...)
3) What mental state arises upon exiting? If one enters with jhana-like concentration, does one exit with that level of concentration? Does one exit around jhana 8? Or is it, like my experience, indistinct?
4) How long can NS be expected to last for someone who has good but certainly not "visuddhimagga-jhana" levels of concentration? What is the shortest amount of time that one is likely to attain NS for? I cannot imagine that the NS-like event I'm wondering about lasts for more than a few minutes, judging by what the clock says.
1) I don't think so; fruition can be experienced without clearly being aware of the blink-out as well and they are similar events.
2) I regarded it as being unremarkable, but that in and of itself was remarkable.
3) I experienced it as being some-what random. Sometimes I just opened my eyes afterward and sat around for a while, and sometimes it seemed as though I was in some kind of jhana afterward which I tinkered around with.
4) I don't know about others nor have I read much about it, but I used a watch to try to estimate the time I was "out" for and usually guessed it was around 4-9 minutes. Tough to say though, since I could not watch the clock while nearing the state, nor is there a sense of time passage while "out." I tried to counter that with a few clever methods, for example, I set a 1-beep alarm to go off every 5 minutes, and then counted the beeps during the session and used that to gauge when the event happened so as to estimate the "out" duration.
Anon Anon:
My overall impression is that, if what I'm experiencing is NS, then the whole thing is very good and worth attaining. I am almost inclined to say that it has a healing, restorative quality to it. The aftereffects last a very long time and if their strength is directly related to the length of time in NS, then (say) 30 minutes of NS must be very powerful indeed. The few minutes of NS I believe I can get give aftereffects that are strong enough to be obvious but not strong enough to count as a "NS-hangover" that would interfere with daily functioning; but if their strength were doubled, it would probably be dangerous to drive a car.
In my opinion, this is as big a sign as anything when diagnosing...I think NS is generally underrated and enjoyed attaining to it when I was able.
Best,
Trent