The Compact Disc (CD) was launched commercially in 1982 by Philips and Sony, introducing the first mass-market digital audio format. Heralded by science outlets like ABC Science as a revolutionary step forward, the format promised superior, noise-free sound quality that rapidly overtook analog vinyl records and cassette tapes. Credit: ABC Science | History In Pictures

Every CD holds its data as a continuous spiral of microscopic dents called pits, with flat areas known as lands in between. Each pit measures about one thousandth the width of a human hair. A CD player reads these by shining a laser onto the surface. Light reflects differently off pits and lands, and those tiny changes in brightness are converted into binary code. That is how sound, video, or files become readable data. Love technology? Follow @Technology Credits: @microscopie_44 #technology #sc