• Discs of matter are found around stars including our own Sun, whose attendant gas and dust disc gives rise to the zodiacal light. Denser disks, like the one from which the solar system condensed, are seen around younger stars. The disc around the star Beta Pictoris is one of the best-observed. Other stars accumulate disc-shaped masses of material, typically by gravitational attraction removing it from companion stars. These are called accretion discs and are seen on a larger scale around some galaxies.
  • A digital optical storage medium, usually 12 centimeters in diameter, whose contained information is encoded in microscopic pits on its metallic surface, which is protected by a plastic layer. To recover the recorded content, a laser is focused on the metallic surface of the disc, and the reflected light is modulated by the code on said disc. Since there is no contact between the pickup and the recorded surface, wear is minimized, while the protective layer helps avoid reading errors due to dust or minor marks on the surface of the disc. Any form of data may be recorded onto a disc, and formats include DVDs, DVD+RWs, CDs, and CD-ROMs. Also called optical disc.
  • synonym disk
  • synonym disk(1)
  • synonym disk

Not what you were looking for?