Voyager Golden Record in the context of "Light-year"

Music is the arrangement of sound to create some combination of form, harmony, melody, rhythm, or otherwise expressive content. Music is generally agreed to be a cultural universal that is present in all human societies. Definitions of music vary widely in substance and approach. While scholars agree that music is defined by a small number of specific elements, there is no consensus as to what these necessary elements are. Music is often characterized as a highly versatile medium for expressing human creativity. Diverse activities are involved in the creation of music, and are often divided into categories of composition, improvisation, and performance. Music may be performed using a wide variety of musical instruments, including the human voice. It can also be composed, sequenced, or otherwise produced to be indirectly played mechanically or electronically, such as via a music box, barrel organ, or digital audio workstation software on a computer.

Music often plays a key role in social events and religious ceremonies. The techniques of making music are often transmitted as part of a cultural tradition. Music is played in public and private contexts, highlighted at events such as festivals and concerts for various different types of ensembles. Music is used in the production of other media, such as in soundtracks to films, TV shows, operas, and video games.

The Voyager Golden Record contains 116 images and a variety of sounds. The items for the record, which is carried on both the Voyager 1 and Voyager 2 spacecraft, were selected for NASA by a committee chaired by Carl Sagan of Cornell University. Included are natural sounds (including some made by animals), musical selections from different cultures and eras, spoken greetings in 55 languages, human sounds like footsteps and laughter, and printed messages from President Jimmy Carter and U.N. Secretary-General Kurt Waldheim.

Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper or silver (to make silver-gilt), by a chemical or electrochemical (electroplating) process. Plating refers to modern coating methods, such as the ones used in the electronics industry, whereas gilding is the decorative covering of an object with gold, which typically involve more traditional methods and much larger objects.

Carl Edward Sagan (/ˈseɪɡən/; SAY-gən; November 9, 1934 – December 20, 1996) was an American astronomer, planetary scientist and science communicator. His best known scientific contribution is his research on the possibility of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by exposure to light. He assembled the first physical messages sent into space, the Pioneer plaque and the Voyager Golden Record, which are universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. He argued in favor of the hypothesis, which has since been accepted, that the high surface temperatures of Venus are the result of the greenhouse effect.

Initially an assistant professor at Harvard, Sagan later moved to Cornell University, where he spent most of his career. He published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books. He wrote many popular science books, such as The Dragons of Eden, Broca's Brain, Pale Blue Dot and The Demon-Haunted World. He also co-wrote and narrated the award-winning 1980 television series Cosmos: A Personal Voyage, which became the most widely watched series in the history of American public television: Cosmos has been seen by at least 500 million people in 60 countries. A book, also called Cosmos, was published to accompany the series. Sagan also wrote a science-fiction novel, published in 1985, called Contact, which became the basis for the 1997 film of the same name. His papers, comprising 595,000 items, are archived in the Library of Congress.