The momentum existing in the form of wave is obviously different from the momentum of moving objects in classical mechanics. Since the advent of quantum mechanics, the understanding of moving particles seems to be only the expression of energy and momentum of particles, but there is no mechanism analysis of the transition of energy and momentum of particles; The key to the problem is that the frequency of fluctuating particles with energy and momentum is never thought to change, nor how it changes. This paper uses the ITCWF (ITCWF--In-Transit Change in Wave Frequency[1]) effect to explain the mechanism of variable wave frequency, that is, the wave can transmit the momentum to the transmission medium. At the same time, it points out that there is a mechanical distribution in the fluid that conforms to the classical mechanics. And waves can naturally occur to discuss the intrinsic relationship between wave dynamics and classical mechanics.

Aims and Scope:

1. ITCWF (ITCWF--In-Transit Change in Wave Frequency
2. Doppler effect
3. Gravity redshift
4. Dispersive Extinction Theory
5. Fractional calculus