[time-nuts] Visual clock comparison
csteinmetz at yandex.com
Sat Apr 18 03:52:32 EDT 2015
>That would make a fun time experiment. One that you should do and
>report back to us.
>I see two experiments: one using LED flashes and one using speaker ticks.
The research has been done with audio tics. Under ideal conditions
-- fast tics (risetime < 1uS, duration < 10uS) mixed electronically
and delivered to one speaker (to avoid differential air path delays
and binaural effects) -- people can steer an adjustable tic into
coincidence with a reference tic with an error of a mS or less. (The
"speakers" used for these experiments are piezoelectric sounders with
acoustic bandwidths in the MHz region, much faster than any moving
I strongly suspect the flashing light (LED, flashtube) experiment has
also been done.
Note that conditions must be optimized -- the output device (LED,
flashtube, speaker) needs to have rise and fall times much shorter
than the expected human perception limit (note that LED optical
switching speeds range from nS to mS), and they need to present to
the subject essentially coincidently (tics mixed electronically and
delivered to one speaker, fast LEDs of the same color immediately
adjacent to each other).
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