Theory of sonics
![No. 55 squadron of DH4s, the first aircraft to go into active service fitted with the C.C. Gear, arrived in France on 6 March 1917.](/Images/godic/202502/20/Airco_DH-44632.jpg")
![Figure I](/Images/godic/202502/20/GoguConstantinescuFigureI_Sonicitysvg4632.png")
![Figure II](/Images/godic/202502/20/GoguConstantinescuRezonanta.svg4632.png")
![Figure III](/Images/godic/202502/20/GoguConstantinescuWaveTransmission.svg4632.png")
The theory of sonics is a branch of continuum mechanics which describes the transmission of mechanical energy through vibrations. The birth of the theory of sonics can be considered the publication of the book A treatise on transmission of power by vibrations in 1918 by the Romanian scientist Gogu Constantinescu.