Sound amplification by stimulated emission of radiation of the laser. In a SASER device, a source (e.g., an electric field as a pump) produces sound waves (lattice vibrations, phonons) that travel through an active medium. In this active medium, a stimulated emission of phonons leads to amplification of the sound waves, resulting in a sound beam coming out of the device. The sound wave beams emitted from such devices are highly coherent. The first successful SASERs were developed in 2009. Instead of a feedback-built wave of electromagnetic radiation (i.e., a laser beam), a SASER delivers a sound wave. SASER may also be referred to as "phonon laser",
A Sound of Thunder changes in the future is a representation of the butterfly effect, and used as an example of how to consider chaos theory and the physics of time travel. A Sound of Thunder "A Sound of Thunder" is a science fiction short story by Ray Bradbury, first published in "Collier's" magazine in the June 28, 1952, issue and Bradbury's collection "The Golden Apples of the Sun" in 1953. In the year 2055, time travel has become a practical reality, and the company Time Safari Inc. offers wealthy adventurers the chance to travel back in time to hunt extinct species such as