"Mysterious aperture" (玄竅) is one the most important concept in Taoist mediation or Neidan (内丹), without a proper understanding of which, a practitioner can't proceed at all, not even able to do a proper microcosmic circulation (小周天). The interesting thing is that many contemporary practitioners simple can't execute the concept in practice, with the result that many falsely believe that doing a proper microcosmic circulation will take years (10+) of practice if can be achieved at all (and to justify their false belief, they further wrongly believe that if they can perform the microcosmic circulation, they will never get sick again for the rest of their lives!) On the other hand, most classic texts said it would only take around 100 days to perfect the microcosmic circulation, and defined this level as the "foundation level".
Recently I browsed a book on Taoist Neidan written by a well-known scholar/teacher/practitioner in Hong Kong (mentioning his name will be unnecessary for my presentation here) and he said that the classics' saying of 100 days was for the brightest students only, normal folks had to spend much more time, some couldn't get it even after more than 10 years of learning (fire the teacher, I will recommend, assuming you're diligent). And he devised many of his own elementary chi-kung exercises for beginners as preparatory practice (the learning of all these exercises will probably take more than a year). I flipped through his book more, I noticed that he had a misunderstanding in the process of establishing the cauldron (the conceptual human body defined by the Ren Mei (任脈) and Du Mei (督脈). The practice as I understand (intellectually and experientially) is as follows:
Only after the establishing the cauldron, the stove (chi center situated at the lower abdomen) can be "set on fire", and the microcosmic circulation need to be activated, and then the mysterious aperture can be established (I shall do in more details in some future posts, otherwise I am going to distract my own logical presentation).
The gist of the matter is, a practitioner has to understand the concept of point-meditation to accomplish the above (In point-mediation, practitioner meditates on a single point (or a coordinated number of points) to establish a chi-center, a prerequisite for establishing the Mysterious Aperture). And point-meditation has been practiced by some famous internal marital artists, check my previous post: Point mediation in advanced martial art workout). Fair to say this is an advanced concept, but the puzzling question remains: why many teachers teaching the stuff (like the author I mentioned above) failed to understand the concept?
As a serious practitioner of both internal martial art and Taoist meditation, I speculate as follows. In the past, practitioners of deep Taoist mediation or Neidan were mostly for the purpose of spirituality. After years of morality training, these practitioners were still not satisfied with the fact that they would occasionally slip back into the realm of "human selfishness". They wanted to train themselves into truly spiritual people with their total self (or personality) being transformed into a highest spiritual reality. And without any better name to name such beings, they called them Immortals. In short, they wanted to train themselves to become Immortals. The path however was difficult, as they learned from their masters, got revelations from previous Immortals during dreaming or meditation, or through reading classic texts. And they understood the gist of the matter was to build up a strong chi. How strong would be needed? There were different stages, and the first stage was to build up chi strong enough that the cauldron could be set up, stove being established, chi in Dantian (丹田) bred the first Mysterious Aperture and the chi could strongly circulate along the Ren Mei and Du Mei as a necessity rather than with conscious effort. Even for the initial foundation level, much continual, disciplined, concentrated and focused effort would be needed in a rather short period of time.
And according to the classics, the above initial stage would take about 100 days. And I can tell you that it can be done in 100 days! Why many practitioners can't? And more specific, why many teachers (like the one I mentioned above) said it can't be done?
Nowadays most people come to Taoist meditation for health reasons rather than spiritual reasons. Therefore they don't have the determination to do intense practice to generate enough chi. And without enough chi, the concept of cauldron, stove, microcosmic circulation, point meditation and mysterious aperture will become academic concepts rather than physical phenomenon that a practitioner can experience (with the result the these students may likely to remain fantasizing to be able to achieve the "great" microcosmic circulation for the rest of their lives).
On the coaching side, in all history, this has always been a most tricky issue, actually applicable to all internal practices in which everything happens inside one's body. As such every "teacher" can claim he knows everything! In the modern world where every profession is up for query (including our doctors and bankers), it has become more the responsibility of a student to find out what, if any, he is learning or can learn from his teachers, assuming he doesn't want to waste his valuable time.