What is the phenomenon of *** vibration, what is its harm, and what are its applications?

When people from the outside world to add a vibration to the object (known as the curative), if the curative force of the frequency and the object's intrinsic frequency is exactly the same, the object vibration amplitude to reach the maximum, this phenomenon is called "*** vibration". Any object itself exists self-oscillation, when an object receives another object's oscillation frequency, and coincidentally with the object's oscillation frequency is the same, so it will produce *** vibration. *** vibration is extremely dangerous and can cause bridges, houses and other buildings to collapse instantly, and even endanger the human heart by rupturing blood vessels. *** vibration technology is widely used in machinery, chemistry, mechanics, electromagnetism, optics and molecular, atomic physics, engineering and technology in almost all fields of science and technology. Such as audio equipment in the vibration of the speaker cone, a variety of stringed instruments in the sound cavity in the *** sound box vibration, etc. using the "mechanical *** vibration"; electromagnetic wave reception and launch the use of the "electromagnetic *** vibration"; laser generated by the use of the "Optical *** vibration"; medical technology has been very popular "nuclear magnetic *** vibration" and so on.