LIQUID CRYSTAL ACOUSTICS. Penn State physicist Jay Patel seeks to understand the optical properties of liquid crystals which, consisting of rod shaped molecules with the ability to polarize light, are regularly employed in electronic displays; an applied voltage lines up the rods and shuts off or turns on transmitted light. So it came as a big surprise when Patel discovered that liquid crystals also have acoustic properties. To be precise, an applied voltage imparts energy to the rod molecules which in turn cause the cavity in which the liquid crystal resides to vibrate. The cavity resonates with an audible frequency that could be heard with the unaided ear. (An analogy: the strings of a violin aren't what make sound; rather they transmit the energy of the bow to the body of the violin whose vibrations are source of the music we hear.) Unsure of the implications of liquid crystal sound (tiny speakers, delay lines for circuits?), Patel and his colleagues suspect that this discovery will lead to a fruitful new research area. (Kim and Patel, Applied Physics Letters, 27 Sept. 1999; contact Patel at jayp@phys.psu.edu; 814-863-8999.)