A Brief History of Time (1991)

Factual error: Hawking explains how time slows as one approaches a black hole's event horizon. To illustrate this a CGI-animated analog wristwatch is shown ticking away the seconds progressively more slowly. It's the kind of watch that ticks intermittently: once each second the hand sweeps one second-long increment around the dial and then waits one more second to sweep another increment. In the animation, the frequency of the ticks lessens, but the speed at which the hand sweeps each increment stays the same. To be consistent, the sweep-speed needs to slow down just as much as the tick-frequency. (00:36:30)