Recent studies on chi indicated that it is a form of energy field. Just like, say, magnetic field. If we can repel two magnets with like-poles facing each other, I don't see why we can't repel "giant magnets" like a person by means of mastery of chi. I understand that the prerequisite to such acts is that the receiving party has to have enough chi for the performer to repel.
Though some will ask if this is reasonable: one can only perform lingkongjing on another party who has chi? Well again it only makes sense. A person skilled in chi is more sensitive to slight changes in chi or his energy field. As such he is also more likely to be affected by his chi. So if I can manipulate his chi from my end, he can be defeated.
If lingkongjing is "useless" against opponents who are not skilled in chi, then what good is it in actual combat? Well, in order to reach the level of mastery of lingkongjing, one has to totally master his chi, and before he can master his chi, he has to totally master his jing, and before he can master his jing, he has to totally master his basic taiji forms (or zhao). So even if a lowly beginner like myself, who has yet to be skilled in the mastery of chi, chooses to have a go at someone like Sim Pooh Ho, I will defintely stand no chance, since he doesn't even have to apply lingkongjing to knock me off my feet..... Well we don't use a gun to shoot those houseflies, do we? A simple flyswap will suffice.
Wu Tunan, in his dying days, said that he had only master fifty percent of what he thought can be achieved in Taiji. And this old man had lived to the ripe old age of 105, and he had started learning martial arts when he is less than ten year old. Nearly a hundred years of study in martial arts. What can be achieved through the study of martial arts is still unknown. I tend to agree with some writers that ultimately we are training our conscious minds to achieve clarity. Prsent day science can only understood less than fifty percent of what our brain is about, even less if we are talking about what our mind can do.
This world is a very big place. If what we have today is the penultimate of what we can achieve, then this world is a very big boring place.
I like what was said in the earlier posts: "maintain a healthy skepticism while keeping an open mind".
Just my thoughts in the wee hours of the day. Meanwhile another video link on Wu Tunan and other grandmasters.http://youtube.com/watch?v=RpSwhc9UBjc