The chinese find a relatively large stash of VERY IMPRESSIVE objects buried 3000 to 5000 years ago. Some of these objects are poured bronze. Check out some of the images of masks with unbeleivably straight lines and organic shapes perfectly mirrored across the y axis. Antikythera mechanism is a bit younger than this (although more complex). History is interesting. Note: I have no idea if the Chinese are lying about this stuff. They are known to hide white skinned red headed mummies so who can tell.