SONIC BANDGAPS, frequency ranges in which sound waves are excluded from a material because of the material's geometrical structure, have been created by researchers in Spain, opening the possibility for a fundamentally new way of soundproofing highways and other sources of noise. Acoustic bandgap materials are analogous to optical bandgap materials (also known as photonic crystals), in which arrangements of thin bars can cause light waves to interfere in carefully controlled ways. Such interference prevents the crystal from transmitting light waves within a certain range of colors (Update 55). Taking inspiration from such photonic crystals, and from a beautiful outdoor sculpture in Madrid, Francisco Meseguer of the Institute of Material Science in Madrid (fmese@fis.upv.es) has designed a metallic structure that produces bandgaps in the audible frequency range for sound waves entering the material from all directions. Described at the recent Acoustical Society of America meeting in Norfolk, this "sound sculpture" consists of one-meter-long metal bars arranged in a hybrid honeycomb-triangular pattern.(See http://www.acoustics.org/meseg2.htm; also see Sanchez-Perez et al., Physical Review Letters, 15 June; Physical Review Focus, 15 June)