In 2000, Vitas, the famous Russian "whistle singer", broke the crystal chandelier on the ceiling during his performance at the Kremlin. Naomi Watts, the "Queen of Scream" in Hollywood, once broke a pane of glass on a hotel balcony by screaming in response to fans' demands. Can singing really break glass? According to physics, high-pitched singing can indeed break glass. Sound is produced by the vibration of objects, and the object that produces the sound is called the sound source. Human singing is generated by the vibration of vocal cords, and the sound waves travel through the air. When the frequency of the high-pitched vocal cords approaches or equals the natural vibration frequency of the glass, the glass will resonate. The greater the energy of the singing, the greater the amplitude of the glass's resonance. When the amplitude of the glass's resonance exceeds the limit that the glass itself can withstand, the glass will be broken.
The process of sound breaking glass Any object has its own natural vibration frequency. When the external driving vibration frequency is close to or equal to the object's natural vibration frequency, the amplitude of the object's forced vibration may reach a very large value, a phenomenon called resonance. For example, the windows of houses facing the street will make noises when passing cars affect them, which is because the frequency of the car's sound is the same or similar to the vibration frequency of the window glass. The natural vibration frequency of resonant objects depends on many factors, such as the material, location, density, shape, and defects of the object itself. The natural vibration frequency of quartz glass is about 2000 Hz, and the frequency of human voices generally does not exceed 2000 Hz, so this kind of sound cannot resonate with the glass. However, some trained high-pitched singers can make their voices approach the high frequency of 2000 Hz, at which point resonance with the glass may occur. At the same time, when the glass itself has defects, the probability of it being broken by singing will be even greater.