We can calculate the height of our eldest grandson from this information. Mi Fei mentioned that his grandson's shoes were one foot long, and Mi Fei was from the Northern Song Dynasty, so this ruler should be a Song ruler. There are different opinions on how long the ruler of the Song Dynasty was. The ruler of the Northern Song Dynasty is about 30.9-32.9 cm, usually about 3 1 cm, so the length of the eldest grandson's shoes is about 3 1 cm. People's feet are about two or three centimeters shorter than shoes. In view of the different shoes of the eldest grandson, we should leave more in front. Let's assume that the eldest grandson's feet are 25 cm long. The length and height of a person's feet are proportional. It is generally believed that his height is seven times that of his feet, but a friend of mine who is engaged in criminal investigation told me that they usually calculate his height according to 6.87 times that of his feet. Then, the height of the eldest grandson is about 25 * 6.87 =171.75cm. Of course, there may be an error of three centimeters in this value, but the height of the eldest grandson 1.65 meters should be no problem.
Now we may think that the height of the great grandson is a bit outrageous. In fact, according to the known data, the height of the eldest grandson is not abrupt among contemporary people. First of all, the eldest grandson's husband, Emperor Taizong, is taller than the average person. "The Biography of Liu Heita in the New Tang Dynasty" records: "In the early Qin Dynasty, the target system was double." That is to say, the bow and arrow used by Emperor Taizong is twice as big as that used by ordinary people, so it is obvious that the arm of Emperor Taizong is longer than that of ordinary people, and under normal circumstances, the arm length is directly proportional to the height, so Emperor Taizong should be taller than ordinary people. Secondly, a pair of Tang Dynasty women's shoes of about 40 yards were unearthed in Astana, Xinjiang. Therefore ... the average height of people in the Tang Dynasty may be higher than modern people think, so it is not surprising that the eldest grandson has such a height.
PS: Finally, an unreliable circumstantial evidence is that Sun Qiang's poem "Spring Tour" mentioned "new peaches on the well, tender willows on the eaves", "butterfly dancing among the flowers" and "singing warblers in the trees" all have high views. So, is it possible that Sun Qiang is high in another way?
Both parents are tall. Li Chenggan is at least 175 cm in height.