|
At
the Air Reed exhibit, viewers watch a flute play a single
note while a strobe light flashes on a nearby screen, creating
the flute's shadow. Near the shadow of the flute, another
shadow can be observed: that of the air stream tumbling into
and out of the flute orifice. A Schlieren projection system
driven by the strobe creates this shadow picture of air oscillating
in and out of the flute. The visitor can adjust the strobe
flash frequency, and when it matches that of the flute sound
exactly, the shadow of the air motion appears to stand still.
As the frequency of the strobe is varied from this frequency,
the rhythmic air motion appears to speed up. This exhibit
allows visitors to see the air as it spills rhythmically across
the orifice of a flute. They can also put their fingers into
or near the flute orifice and see the shadow of their finger
and its effect on the air flow at the same time that they
hear the effect of their finger on the sound.
|