The meaning of the name of the point SP-4 (Gong Sun) is the subject of much discussion. I have never been convinced by the translation of Gong Sun as "Grandfather-grandson" (or rather grandchild). Besides being the Luo point of the Spleen, SP-4 is also the master point of the Chong Mai.
Although the translation of Gong Sun as "grandfather-grandchild" is possible, I think there is at least another possible explanation. "Gong" may also mean "general" and "sun" may also mean "second-growth", i.e. the second growth of a plant after pruning later in the season (like a rose for example). Thus, Gong Sun may be translated as "general second growth". What is this second growth? In my opinion, it is the image of the smaller branches stemming from a central stem. This is the image of the Main channels - the main stem - and of the Luo channels which branch out from the Main channels. This image is consistent with the point SP-4 for two reasons: first, because it is a Luo point; secondly because the Chong Mai controls all Luo channels.
There is another connection between the "second growth" and this point's name. The term "Sun" is also the term used in the Nei Jing to indicate the Minute Luo channels, i.e. the small Luo channels that stem from the Luo channels themselves: thus, while the Luo channels branch off from the Main channels, the Sun Luo branch off from the Luo channels themselves (and they are smaller). Thus, Gong Sun may be translated as "General Sun channels": this translation also makes sense because the Chong Mai controls all Sun Luo channels too.
孙 SUN
Finally, there is another possible and easy translation. Gong Sun was also the family name of the Yellow Emperor and we can therefore interpret this point's name as a reference to the Yellow Emperor. This translation would also make sense because the Chong Mai is the "emperor" of the extraordinary vessels, because it is the centre of the energetic vortex created by them. In old times, the extraordinary vessels were compared to members of a family and the Chong Mai was the "father", i.e. the most important member (in a traditional, Confucian view of the family).
Although the translation of Gong Sun as "grandfather-grandchild" is possible, I think there is at least another possible explanation. "Gong" may also mean "general" and "sun" may also mean "second-growth", i.e. the second growth of a plant after pruning later in the season (like a rose for example). Thus, Gong Sun may be translated as "general second growth". What is this second growth? In my opinion, it is the image of the smaller branches stemming from a central stem. This is the image of the Main channels - the main stem - and of the Luo channels which branch out from the Main channels. This image is consistent with the point SP-4 for two reasons: first, because it is a Luo point; secondly because the Chong Mai controls all Luo channels.
There is another connection between the "second growth" and this point's name. The term "Sun" is also the term used in the Nei Jing to indicate the Minute Luo channels, i.e. the small Luo channels that stem from the Luo channels themselves: thus, while the Luo channels branch off from the Main channels, the Sun Luo branch off from the Luo channels themselves (and they are smaller). Thus, Gong Sun may be translated as "General Sun channels": this translation also makes sense because the Chong Mai controls all Sun Luo channels too.
孙 SUN
Finally, there is another possible and easy translation. Gong Sun was also the family name of the Yellow Emperor and we can therefore interpret this point's name as a reference to the Yellow Emperor. This translation would also make sense because the Chong Mai is the "emperor" of the extraordinary vessels, because it is the centre of the energetic vortex created by them. In old times, the extraordinary vessels were compared to members of a family and the Chong Mai was the "father", i.e. the most important member (in a traditional, Confucian view of the family).
