they weren't the 1st to make a jet engine in the world. they were the 1st to utilize the principles behind jet propulsion for practical purposes. yes, they were the 1st to make rockets back in the 13th century during the Tang dynasty. If you must know, that was the golden age of chinese civilization. After the Tang, the place was literally bastardized by the Mongolian Yuan who foisted their version of Chinese and warlike barbarism onto the world's most advanced civilization at the time. China never recovered it's pre-eminence and after this event, stayed forever a sick man of the east. If you need further evidence go and check out Mongolia and see how far along they have come.
It is for this reason, I support the speaking of dialects which are a true indication of our origin rather than the Mongolized huayi standardized northern dialect from khanbaliq that we are now all forced to learn.