A lot of information, but as I read all of this, I'm not sure there's a lot of science. Further analysis of the concept of dim mak comes from other students of the system; the following is a very careful analysis of dim mak relevant to related Chinese traditions:

A great deal has been said and written about the Death Touch (Dim Mak) by many people who proclaim themselves experts of this almost forgotten art from the rich traditions of Chinese Martial Arts. Very few of these self-proclaimed "experts" can really explain or perform this feat.

There are great similarities in theory between the studies of Dim Mak and accupuncture. Dim Mak, however, uses a special set of vital pressure points which must be co-ordinated with various secret times of the day, night and seasons.

The Wing Chun secret script states that the vulnerability of a defined vital pressure point depends on the different time and different season and, if damaged, can determine a person's life or death. Such damage can cause serious illness such as convulsions, cramps, coughing of blood, lack of energy and insomnia. A person injured by the Death Touch must seek proper medical treatment, or it would certainly cost him his life. Some would take less than a day, some up to six months. This is why the Dim Mak is also called the Delayed Death Touch.

The Death Touch or Dim Mak is a specialised technique requiring the striking of a particular vital pressure point at a certain time of day and season. This deadly art was developed by the highly skilled Kung Fu practicioners through the centuries, and is based on the similar principles of the relationship between the vital pressure points to various organs and the life sources.

Because Wing Chun style was developed by a woman, the emphasis is on the efficiency of the strike, and Dim Mak is one of its secret specialities. Nevertheless, a lot of the training is devoted to healing the victims of the Death Touch with the use of different combinations of herbal formulae and pressure point massage.

According to the Wing Chun Death Touch secret, a person has some 18 prime vital pressure points, and 54 secondary vital pressure points, to make up 72 vital pressure points. The different seasons (Spring, Summer, Autumn and Winter), and the different times of the day, determine the vulnerability of the pressure point. Some of these pressure points are selected from the 34 known meridians, and some are not.

There is a special way of striking and applying the force to obtain the optimum result. Usually one would use a Phoenix Knuckle as a weapon for striking. A more advanced practioner might be able to use his finger as a weapon.

Wing Chun has a unique Dim Mak system. The following are two ancient diagrams for the front and the back of the body. Referring to the doctrine the vulnerable pressure points circulate according to four seasons - spring, summer, autumn, winter. Each day is divided into twelve segments of time equivalent to two hours. Striking on the vital pressure points corresponding to the timetable will cause serious injury or can lead to death. Hence the meridians correspond to the vital organs. If the Chi in the meridians is blocked due to injury from the Dim Mak strike, the corresponding organ will cease to function. Further, with the law of the five elements, this will lead to the collapse of all other organs. If the victim is not treated properly, death will be inevitable. Therefore it is called Delayed Death Touch.  (Unknown author)