Sound is one of the earliest physical phenomena studied by human. Acoustics is the only branch of physics with the longest history and still in the forefront. From ancient times until the 19th century, sound was understood as a synonym for audible sound. In the pre-qin period of China, it was said: "love originated fromHenan xinyang unearthed PanChi chimesSound, sound is called "voice", "sound and music". Sound, sound, and music are different, but they all refer to phenomena that can be heard. At the same time, it is also said that "ordinary sound", the sense caused by sound (sound sense) is sound, but also called sound, and the modern definition of sound is the same. The same is true in the west, where the etymology of acoustics comes from the Greek word akoustikos, meaning "hearing." The world's first acoustic work was in music."Lu shi chunqiu" records, the yellow emperor ordered ling lun to take bamboo for the rule, increasing the length into twelve rules; Fu xi for the harp, three profit and loss into the thirteen. The three-cent profit and loss method, in which the pipe (flute, flute) is lengthened by a third or shortened by a third, sounds very harmonious, was the earliest acoustic law. It is said that in Greek times Pythagoras proposed a similar law of nature (but with strings as the basis). China henan xinyang unearthed in 1957 PanChi chimes is to commemorate the 525 b.c., the state of jin and chu operations while casting. Its scale is completely in accordance with the natural law, the tone is pure, can be used to play modern music, this is the ancient Chinese acoustic achievements of proof. In the next two thousand years, the study of music has made a lot of progress.In 1584, zhu zaiyu of the Ming dynasty proposed the law of equalization, which is exactly the same as that used in modern western instrument manufacturing, but 300 years earlier. In ancient times, except for the understanding of the mode of sound transmission, the understanding of the nature of sound is exactly the same as today. In both the east and the west, it is believed that sound is produced by the movement of objects, in the air in a certain way to the human ear, causing human hearing. This realization seems simple now, but from the ancient people's level of knowledge, it is remarkable. For example, for a long time the ancient people did not have a correct understanding of the light and heat they encountered in daily life, until the time of Newton when there was a dispute over the particle theory of light and the wave theory, and the particle theory prevailed. As for heat, the theory of "hot matter" lasted longer, and was criticized by f. Engels until the late 19th century.
- Feb 11, 2020-