Chi is not a testable entity. Wine is. The argument that follows thus is false:
Science can't say for sure which wines taste better - or if there is any difference at all. Therefore it follows that science can't be expected to tell how chi works, or even what it is!
Firstly... I can prove that wine exists. Can't do the same for chi. Secondly, the whole "can't prove taste" thing is on shaky ground all by itself regardless.
Next, any experiences of so-called "supernatural" abilities (ESP and the like) must be assumed false until proved legitimate - especially if they are the experiences of the individual, it is that individuals duty as a thinking being to view those experiences as suspect until proved otherwise. This is because the area of perception that a human has access to is not only particularly narrow, but quite often just plain unreliable. The individual perspective is not trustworthy, and no faith should be placed in the experiences of an individual (including the self) without testable evidence (viewable and documented by various sources or witnesses). And even then there could always be evidence in the future which disproves and earlier assertion. Otherwise we enter the realm of "pseudo-mysticism" some strange conglomeration of un-testable belief accompanied by dogma. This draws the mind away from actually learning about the world - experiencing existence - and into the realm of fantasy, in the worst cases, dragging others along with it for the ride. Hello cult. Hello religion.
This is not to say that something like chi doesn't exist! Far from it - I believe that there are dimensions (perhaps quite literally) that lie outside not merely human perception, but human cognitive understanding - at least at present. Heck, a great number of our theories prove that this is, indeed, the case. We understand why things work, but don't always get the "why". We reduce the universe to an ever-smaller equation, and we get... yet another, smaller, equation. This, to me, is beautiful, and filled with endless possibility and wonder. Indeed, it's far more fascinating than the fantasies the mind is capable of coming up with when confronted by the concepts of the - by definition - unknowable.