"In physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, like solids and some liquids. Often designated a quasiparticle, it represents an excited state in the quantum mechanical quantization of the modes of vibrations of elastic structures of interacting particles.
Phonons play a major role in many of the physical properties of condensed matter, like thermal conductivity and electrical conductivity. The study of phonons is an important part of condensed matter physics.
The concept of phonons was introduced in 1932 by Soviet physicist Igor Tamm. The name phonon comes from the Greek word φωνή (phonē), which translates to sound or voice because long-wavelength phonons GIVE RISE TO SOUND. Shorter-wavelength higher-frequency phonons are responsible for the majority of the thermal capacity of solids.
A phonon is a quantum mechanical description of an elementary vibrational motion in which a lattice of atoms or molecules uniformly oscillates at a single frequency. In classical mechanics this designates a normal mode of vibration. Normal modes are important because any arbitrary lattice vibration can be considered to be a superposition of these elementary vibration modes (cf. Fourier analysis). While normal modes are wave-like phenomena in classical mechanics, phonons have particle-like properties too, in a way related to the wave–particle duality of quantum mechanics."

"The conversion of one element (specifically one isotope) to another through a dimensional reaction occurs under select conditions of phonon resonance. Dimensional phonon resonance occurs when the space occupied by one isotope is exactly the same as that of another isotope in its rest state. This event only occur under the following two conditions: the expansion of an isotope by heating; or, the contraction of an isotope by cooling."