"Today we make things at the molecular scale by stirring together molecular parts and cleverly arranging things so they spontaneously go somewhere useful. In the future we'll have molecular "hands" that will let us put molecular parts exactly where we want them, vastly increasing the range of molecular structures we can build."Ralph Merkle
Drexler's solution is a device he calls an assembler. Essentially an assembler is a nano-machine that is able to build other nano-machines. If you have just one working assembler and you give it the required feedlot, that device can then construct more assemblers, which in turn can build anything you want them to (assuming you have the blueprints).
The theoretical concept of machine duplication is well-developed. For example one can write a C program that prints out an exact copy of itself. Such a program would have 808 bits of information. The Morris Worm (somewhat akin to a computter virus) that paralysed the Internet in December 1988 had half a million. The common E. coli bacterium has over 9 million, and a Drexlerian assembler 100 million. A human body has about 6.4 billion
The basic general-purpose assembler, as proposed by Eric Drexler (above, left) and Ralph Merkle (above, right), would essentially be a stiff telescoping molecular robotic arm, anchored to the substrate and immersed in feedstock. The free end would grab molecular fragments in the feedstock and hold them stiffly enough for them to react with (join) the object being assembled. Such a device would be about 100 nanometers (one ten-thousandth of a millimetre) long and contain about 4 million atoms, about the size of your average virus. It would have six degrees of freedom of movement, and because of its tiny size, be able to move astonishingly quickly.
images not loading? | error messages? | broken links? | suggestions? | criticism?