A display case shows the progression of storage
disks, starting with
one from 1965 that's the size of a tractor-trailer tire. It held 2.5
megabytes of data and had to be sandblasted to be erased.
Had to be sandblasted to be erased? Huh??
Obviously, any sort of read/write device can be erased through writing of
different content. Only a "write-once" device would require destructive
erasure.
We've seen that particular bit of silliness before. Once an authoritative
statement of wrong information is made, others will follow, and if/when
challenged merely refer to the authority.
Quite a while back, we discussed some systems for LONG-term data storage.
Stonehenge was [jokingly] mentioned as being a hard-sectored long term
data storage device. (probably stationary media with moving head)
Assuming a high data density stored as surface markings or pitting,
sandblasting WOULD be the needed method for erasing surface data. How
long before our silly speculation finds its way into the computer
histories, and later generations are told that the druids invented
hard-sectored disks?