- Bellatrix (stars.astro.illinois.edu)
BELLATRIX (Gamma Orionis). If constellations could talk, they might well shout “unfair” at great Orion, the Hunter, one of only four constellations to have two first magnitude stars (the others Crux, the Southern Cross, Centaurus, the Centaur, and Canis Major, Orion’s Hunting Dog).
- Phonograph (Wikipedia)
A phonograph, later called a gramophone (as a trademark since 1887, as a generic name in the UK since 1910), and since the 1940s a record player, or more recently a turntable, is a device for the mechanical and analogue reproduction of recorded sound. The sound vibration waveforms are recorded as corresponding physical deviations of a helical or spiral groove engraved, etched, incised, or impressed into the surface of a rotating cylinder or disc, called a “record”. To recreate the sound, the surface is similarly rotated while a playback stylus (or “needle”) traces the groove and is therefore vibrated by it, faintly reproducing the recorded sound. In early acoustic phonographs, the stylus vibrated a diaphragm that produced sound waves coupled to the open air through a flaring horn, or directly to the listener’s ears through stethoscope-type earphones.