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"The prototype is made of a square of quartz two centimeters wide and two millimeters thick. It houses four layers of dots that are created with a femtosecond laser, which produces extremely short pulses of light. The dots represent information in binary form, a standard that should be comprehensible even in the distant future and can be read with a basic optical microscope. Because the layers are embedded, surface erosion would not affect them." -The American Scientific Journal