Question

rate of spontaneous emission to the stimulated emission in sun ? is laser action possible in sun?

Answer 1

The rate of spontaneous emission to the stimulated emission in sun can be expressed as

$$r=\frac{A}{B},$$

where A - the rate of spontaneous emission, B - the rate of stimulated emission.

Laser action possible in the sun with very low probability for a very short time because laser action must suffice several requirements achieved only in devices called lasers.