Images Dated 11th October 2000

Compact disc surface

Compact disc surface. Coloured scanning electron micrograph (SEM) of the surface of an audio compact disc exposed to show the musical layer below. The plastic disc is pressed with a series of fine depressions representing a digitised musical signal capable of being read by a laser. To reflect the laser light, the music layer is coated with a fine film of metal which follows the depressions exactly. This layer is covered by another layer of transparent plastic (upper right). The music is sandwiched between two layers of plastic which prevents dust and scratches from affecting the sound. Magnification: x3, 450 at 5x7cm size

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