Sound amplification by stimulated emission of radiation the axes of the mirrors, it is possible for photons to repeat multiple reflections and force more and more photons to follow them producing an avalanche effect. The number of photons of this coherent laser beam increases and competes the number of photons perished due to losses. The basic necessary condition for the generation of a laser radiation is the population inversion, which can be achieved either by exciting atoms and inducing percussion or by external radiation absorption. A SASER device mimics this procedure using a source-pump to induce a sound beam of phonons. This sound beam propagates not in
A Boy, a Girl and a Bike gave the film two out of five stars, calling it, "A minor, good-natured British comedy romance." A Boy, a Girl and a Bike A Boy, a Girl and a Bike is a 1949 British romantic comedy film directed by Ralph Smart and starring John McCallum, Honor Blackman and Patrick Holt. The film's art direction was by George Provis. The film concerns the romantic escapades and adventures of a Yorkshire cycling club. Young couple Sue (Honor Blackman) and Sam (Patrick Holt) are members of a Yorkshire cycling club, the ‘Wakeford Wheelers’. Romantic complications ensue when wealthy David (John McCallum) becomes smitten