Drop dynamics research deals with the behavior of liquid drops and gas bubbles under the influence of external forces and chemical effects. This research provides a foundation for understanding scientific and technological areas in which drops and bubbles have a role, from rain in the atmosphere to chemical processes. Scientists are also interested in studying single bubbles and drops as models for other natural systems. Investigators can manipulate the spherical drops using sound and other impulses, creating an interactive model for processes such as atom fissioning.
Capillarity refers to a class of effects that depend on surface tension.
These changes, or capillary effects, often occur in liquids on Earth, but are to some degree masked or minimized by the stronger force of gravity. In microgravity, however, capillary effects become prominent. Promising micro-gravity research subjects in this area include weak fluid flows, such as those found in poorly conducting fluids in a magnetic field, and Joule heating, which is heating a material by flowing an electric current through it. In Earth's gravity, Joule heating causes buoyancy-driven flows that, in turn, obscure its effects. An example of such processes is elec-trophoresis, which is the use of electric fields to separate biological materials.