- 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.
- Thomas Edison (Wikipedia)
Thomas Alva Edison (February 11, 1847 – October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventions, which include the phonograph, the motion picture camera, and early versions of the electric light bulb, have had a widespread impact on the modern industrialized world. He was one of the first inventors to apply the principles of organized science and teamwork to the process of invention, working with many researchers and employees. He established the first industrial research laboratory.
- Mount Rushmore (Wikipedia)
The Mount Rushmore National Memorial is a national memorial centered on a colossal sculpture carved into the granite face of Mount Rushmore (Lakota: Tȟuŋkášila Šákpe, or Six Grandfathers) in the Black Hills near Keystone, South Dakota, United States. Sculptor Gutzon Borglum designed the sculpture, called Shrine of Democracy, and oversaw the project’s execution from 1927 to 1941 with the help of his son, Lincoln Borglum. The sculpture features the 60-foot-tall (18 m) heads of four United States presidents: George Washington, Thomas Jefferson, Theodore Roosevelt, and Abraham Lincoln, chosen to represent the nation’s birth, growth, development, and preservation, respectively. Mount Rushmore attracts more than two million visitors annually to the memorial park which covers 1,278 acres (2.00 sq mi; 5.17 km2). The mountain’s elevation is 5,725 feet (1,745 m) above sea level.