The computer files you store on thumb drives, DVDs, external hard drives, or tapes aren’t eternal. Digital can be forever because 1s and 0s aren’t ambiguous, but the material they’re recorded on usually is less stable. Micro-circuitry is easily damaged by random electric sparks. Plastic deteriorates. Mechanisms eventually fail. Magnetic coatings separate from their supports. The data can persist if the data is continually re-written to new devices, but the processes of reading and writing aren’t flawless. Now, however, lasers can etch 3-D patterns into a quartz disk that will last billions of years and in high densities. One disk can hold 360 terabytes. This won’t affect most people, but it will mean that we’re less likely to have the digital equivalent of a Library of Alexandria moment, when an entire era’s knowledge was eliminated by a single event like an EMP or cosmic event.
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