Spontaneous emission and neutron decay

https://en.wikipedia.org/wiki/Spontaneous_emission

• https://en.wikipedia.org/wiki/Stimulated_emission

• 2016 - Sidney Nagel, Burton Echoes from Anharmonic Normal Modes in Model Glasses

We show that these echoes are due to anharmonic, weakly-coupled vibrational modes, and perhaps provide an alternative explanation for the phonon echoes observed in glasses at low temperatures

We offer **an

2016 Random Nonlinear Infinite-Level-System Model for Amorphous Solid Phonon Echo and Saturation Phenomena
Di Zhou, Anthony J. Leggett

https://en.wikipedia.org/wiki/Free_neutron_decay

in free space