In the early days of television broadcasting, engineers worried about the problem of keeping audio and video signals synchronized.
Then they accidentally discovered that they had around a hundred milliseconds of slop: as long as the signals arrived within this window, viewers’ brains would automatically resynchronize the signals; outside that tenth-of-a-second window, it suddenly looked like a badly dubbed movie.
[Excerpted from “Brain Time” by David Eagleman]
LOL.. 50 years from now, they’ll say the same thing about the early years of online video. Ever see those out-of-sync youtube clips?