This award supports a series of projects in the general area of single- and multi-bubble sonoluminescence. One set of experiments will seek to determine if there is any fundamental relationship between the continuum emission in single-bubble sonoluminescence and the underlying continuum associated with multi-bubble sonoluminescence, in particular, as a function of the solvent being used. Attempts will be made to create an environment in which stable single-bubble sonoluminescence can exist. The robustness of single-bubble sonoluminescence under different circumstances will be studied as a means of identifying the underlying principles causing the phenomenon to occur.