why do Chinese show their ancestors can fly in their movies ?

yes, there's a historical background in chinese mythology about "super" hero martial arts warriors that gain supernatural powers after many years of training, you can read many of those stories in ancient "wuxia" books, literally they are "the super hero comic books" of ancient china..

http://en.wikipedia.org/wiki/Wuxia

"While wuxia as the name of a genre is a recent coinage, stories about the xia date back more than two thousand years. Wuxia stories have their roots in some early youxia stories from 300–200 BC."

"The martial arts in wuxia stories are based on factual wushu techniques and other Chinese martial arts. However, the mastery of such skills are highly exaggerated in wuxia stories to fictitious and superhuman levels of achievement and prowess. For example, ordinary blows such as kicks or punches can have devastating effects on characters in wuxia fiction, and certain characters who are formidable martial artists can even project streams of energy at opponents to knock them down or stun them. The projection of these energy streams and their impacts can even lead to explosions."

" Qinggong is based on real Chinese martial arts. Some real-life martial artists such as those who practice baguazhang, train in qinggong for years by attaching heavy weights onto their legs.However, its use is highly exaggerated in wuxia stories and films in which characters can circumvent gravity and literally fly."

the closest example of supernatural martial arts powers that we can find in the real world of today are the shaolin martial artists.

here's a example of a shaolin "supernatural trick" that defies the logic of science..

http://www.youtube.com/watch?v=0Z1Rm4ANFl8

(starts about 3 minutes in the video the spear in the neck test)

Do you mean, could Chinese people really fly 300 years ago?

What do you think?

It's fantasy. People can do anything in movies!

Yes! they can fly.. They discovered opium long time ago

It's called fantasy

Americans have superheroes in comic books...what's the difference?

because they really could fly---obviously!