Instructions: Keep your eyes fixed on the small white mark in the center. At first, the ring is stationary and it’s easy to tell that the dots are changing. A few seconds later, the ring begins to rotate and the dots suddenly appear to stop changing. (Or, more precisely, they appear to change much less than when the dots are motionless.)
But play the movie again, this time looking directly at one of the dots and following it as the ring rotates. You will see that, in fact, the dots had been changing at the same rate the whole time, even during the rotation—you just didn’t notice it. This failure to detect that moving objects are changing is silencing.
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