Scientific terminology informal or non-technical English, to say "strictly speaking" for "sensu stricto" and "broadly speaking" and so on is valid. Even in formal writing, there is no formal requirement to use the Latin terms rather than the vernacular. Valid reasons for using these Latin or partly Latin expressions are not points of pretentiousness; they include: A good example is the word "laser", an acronym for "Light Amplification by Stimulated Emission of Radiation", and therefore all its letters should be capitalized. However, because of frequent use, this acronym became a neologism, i.e., it has integrated into English and most other languages. Consequently,
Stimulated emission given by where the proportionality constant "B" is known as the "Einstein B coefficient" for that particular transition, and "ρ"("ν") is the radiation density of the incident field at frequency "ν". The rate of emission is thus proportional to the number of atoms in the excited state "N", and to the density of incident photons. At the same time, there will be a process of atomic absorption which "removes" energy from the field while raising electrons from the lower state to the upper state. Its rate is given by an essentially identical equation, The rate of absorption is thus proportional