Abstract: Methods (and apparatus) for nondestructively testing a body of material having a surface in contact with a gaseous environment (e.g. air, nitrogen, or inert gas), that comprise (A) the step of (and means for) directing to a region at the surface of the body a pulse of laser radiation having sufficient energy density and sufficiently long wavelength to initiate in the adjacent gas a blast wave that impinges on the surface and provides an ultrasonic wave in the body, and (B) the further step of (and means for) detecting a portion of the ultrasonic wave that has been affected by the body. The radiation directing means typically comprises a laser that provides a pulse having a duration of about 0.01 to 10 microseconds, and means for focusing the pulse to provide an energy density of at least about 5 Joules per square centimeter. The detecting means typically comprises an electromagnetic or capacitive transducer.