The rate of spontaneous emission depends partly on the environment of a light source.

This means that by placing the light source in a special environment, the rate of spontaneous emission can be modified.

In other words, spontaneous emission (the mirror image of absorption) would be prevented.

For these conditions, coherent processes contribute significantly to the spontaneous emission.

Clearly, the rate of spontaneous emission in free space increases with .

Human ears generate their own noises, called spontaneous otoacoustic emissions, which about 30% of people hear.

But the question of whether these structures can encourage spontaneous emission in specific directions remained open.

Thus, the rate of transitions between two stationary states is enhanced beyond that due to spontaneous emission.

If the rate of spontaneous emission, or any of the other rates are fast, the lifetime is short.

Sometimes there are complications-bleeding, spontaneous emissions, that sort of thing.