  Almost 50 years ago Bob Brodkey and his student, Corino, conceived of and
carried out a visualization experiment for the very near wall region of a
turbulent pipe flow that, together with the turbulent boundary layer
visualization of Kline et al., excited the turbulence research community. Using
a high speed movie camera mounted on a lathe bed that recorded magnified images
in a frame of reference moving with the flow, they observed the motions of
sub-micron particles in the sub-, buffer- and log-layers. Surprisingly, these
motions were not nearly so locally random as was the general view of turbulence
at the time. Rather, connected regions of the near wall flow decelerated and
then erupted away from the wall in what they called "ejections". These
decelerated motions were followed by larger scale connected motions toward the
wall from above that they called "sweeps". They estimated that ejections
accounted for $70\%$ of the Reynolds shear stress at $Re_d = 20,000$ while only
occurring about $18\%$ of the time. This fluid dynamics video shows short
sequences, at three Reynolds numbers, from the original Corino and Brodkey
visual study. In the following decades it inspired numerous laboratory and
simulation studies aimed at unraveling the structure of bounded turbulent flows
and understanding the turbulent transport processes within them.
