Remember those first dot-matrix printers that an ordinary Joe could afford? We were thrilled. A new way of writing and communicating. Gone were the pencils and yellow legal pads, the two-finger typing, and the bottles of white-out; now we wrote and revised on screen and printed a finished product. Most writers felt their creativity enhanced.
That was just the beginning. Ink-jet and laser printers soon followed, along with ever more sophisticated compositional and formatting software. Today a writer can self-publish books. One can debate whether this has been good or bad for writing and publishing, but it cannot be denied that we have lived through a revolution.
We are about to live through another. Enter 3-D printers.
They've been around for a few years, although expensive. They can print in plastic, metal, or ceramic any object (of a limited size) you can describe with digital software. (Watch the video on the Wiki site.) Many science labs are now using 3-D printers to fabricate experimental equipment, more cheaply than can be done by traditional machine shops.
In recent years, science journals have been printing 3-D stereo images, typically of biomolecules, to be viewed with colored glasses. Soon, if not already, they will offer links to software for printing 3-D models.
I notice on the internet that 3-D printers are now available at home hobbyist prices. Sites like Thingiverse offer thousands of free digital designs for printable objects. This strikes me as more or less the dot-matrix stage of 2-D printing.
But here's the thing that interests me. Some 3-D printers can print many of their own parts. Is this a step on the way to self-reproducing machines? Don't laugh. I remember when we thought Pong was a hotshot computer game.