“William James, wondering more than a century ago what is ‘the minimum amount of duration which we can distinctly feel,’ had it pegged around 50 milliseconds [which is 1/20th of a second, or about the duration of this frame]. James cited the seminal work of Austrian physiologist Sigmund Exner, who observed that people shown sets of flashing sparks stopped being able to recognize them as distinct entities around 0.044 seconds.” So now you know. ⠀