But like all great inventors they were ahead of their time.

On this sixtieth anniversary of the patent application they filed, it seems appropriate to pause and remember their remarkable accomplishment.

Silver dreamed up the apparatus, for the most part. The early concepts called for a 500-watt light bulb and ultraviolet ink; it was all mechanically unwieldy and prohibitively expensive. Nevertheless, the basics were all there, and an inhabitant of the 21st century would probably grasp its purpose right away, even if someone from Silver and Woodland's own time would be completely baffled.

The method was envisioned by Woodland. He stood on the beach one day and drew a Morse code message with his foot. He found that by vertically extending the dots and dashes he could create a visual code of wide and narrow lines that Silver's apparatus might recognize.

More than two decades passed before technology caught up with their idea. And even more time passed before the initial resistance to their invention fell, before people stopped believing that it was a subversive plot, or a symbol of crushing conformity, or even the Mark of the Beast. Before it became just a mundane part of our everyday lives, hardly worth thinking about.

And that, in a nutshell, is the story of technology itself.