The breakup of viscous and viscoelastic drops in the
high speed airstream behind a shock wave in a shock tube was photographed with
a rotating drum camera giving one photograph every 
. From these photographs we created movies of the fragmentation
history of viscous drops of widely varying viscosity, and viscoelastic drops,
at very high Weber and Reynolds numbers. Drops of the order of one millimeter
are reduced to droplet clouds and possibly to vapor in times less than 
. The movies may be viewed at
http://www.aem.umn.edu/research/Aerodynamic_Breakup. They reveal sequences of
breakup events which were previously unavailable for study. Bag and
bag-and-stamen breakup can be seen at very high Weber numbers, in the regime of
breakup previously called “catastrophic.” The movies allow us to generate
precise displacement-time graphs from which accurate values of acceleration (of
orders 104 to 105 times the acceleration of gravity) are
computed. These large accelerations from gas to liquid put the flattened drops
at high risk to Rayleigh-Taylor instabilities. The most unstable
Rayleigh-Taylor wave fits nearly perfectly with waves measured on enhanced
images of drops from the movies, but the effects of viscosity cannot be neglected.
Other features of drop breakup under extreme conditions, not treated here, are
available on our Web site.