10 Facts about CDs:
- Compact disc (CD) was co-developed by Philips and
Sony and was first released in Japan in October 1982.
- Physical Dimensions: A standard CD has a diameter of
120 mm (4.7 inches) and is 1.2 mm thick.
- Storage Capacity: CDs typically hold up to 74 minutes
of uncompressed stereo audio or approximately 650 MB of data, although
some can store up to 80 minutes or more.
- Laser Technology: CDs are read using a laser beam
that measures the reflection of light off the disc's surface, where data
is encoded in the form of tiny pits and lands.
- Formats: The CD format has evolved into several
types, including CD-ROM for data storage, CD-R for recordable discs, and
CD-RW for rewritable discs.
- Market Impact: By the early 1990s, CDs had outsold
vinyl records and cassette tapes in the U.S., capturing over 90% of the
music sales market by 2000.
- Error Correction: CD players perform error correction
by making calculations to fill in missing data, which is a common
occurrence due to scratches or other imperfections on the disc.
- Compatibility: Most DVD and Blu-ray players are
backward compatible with CDs, allowing them to play audio CDs alongside
newer formats.
- Production Process: The manufacturing of CDs involves
creating a glass master that is used to produce multiple copies through a
process involving polycarbonate molding and aluminum coating.
- Decline in Use: The rise of digital downloads and streaming services in the mid-2000s led to a significant decline in CD sales, marking the end of the CD's dominance in music distribution.
