Scientific innovation started to decline in the roman empire true or false?

I would say true. Goldsworthy wrote that Roman industrial output appeared to peak in the early empire, and mining enterprises in Spain made use of hydrologic drills or some such. But basically the Empire didn't progress technically. According to Ferrill, it actually regressed in the late Empire, in terms of infantry equipment. The emperor Tiberius is said to have put an inventor to death. Also, look at the confused notions of astronomer Claudius Ptolemy. Lack of much progress partly explains the fall of the western empire. "Civilized" then didn't mean having better technology; even barbarians had basically the same weapons.