Why do DVDs last longer than video tapes?
Videotapes are made of a material that is subject to the effects of stray magnetic fields, temperature, and humidity, as well as the wear and tear of passing across the reading heads in the VCR. Even if videotapes are never viewed, the tape material will gradually degrade, resulting in images and sound of poor quality, and eventually, an unviewable, unrecoverable tape. DVDs, on the other hand, are not magnetic (they are optical, and unaffected by stray fields of any kind), and they do not come in contact with the reading devices in the DVD player. Therefore, a DVD can be expected to last for at least 100 years.
