Why did Sun Dianying steal Emperor Qianlong's Yuling?

While Sun Dianying was stealing the mausoleum of Empress Dowager Cixi, other soldiers were also robbing the Yuling of Emperor Qianlong. At the same time, something strange happened. Six people, including Gan Long, Empress Xiao Xianchun and Emperor Guifei of Zhejiang and Fujian, were buried in Yuling. After the heavy coffin of Qianlong was placed on the stone bed of the underground palace, four heavy dragon stones were placed in the four corners of the coffin in order to determine the feng shui line and mark the most prosperous position in Long Mai. After Sun Dianying successfully opened the front door, the last one really became an obstacle, and it didn't help. The feeling be nasty under, had to explode. After the Shimen explosion, the soldiers were surprised to find a great miracle: the other five coffins were all on the stone bed, and they "walked" down alone, holding on to the Shimen tightly, so the soldiers could not open the door.

Did Qianlong secretly know that thieves would come to steal Yuling and "down" the top door himself? The same strange scene appeared again in 1975 when archaeologists cleaned the Yuling underground palace. Qianlong's coffin "walked" down against the stone gate again this time, playing the role of a natural stone. Some experts believe that this is due to the buoyancy of the leaked groundwater, which makes the coffin float. But why don't the other five move? Moreover, the four corners of the dried catalpa coffin are fixed with heavy stones. If it is due to the buoyancy of groundwater, there will be great waves, but the infiltrated water obviously does not have this condition. So far, experts have failed to come up with convincing archaeological findings to prove why Gan Long's coffin moved around and "cared" for his grave, which became a mystery.