Archived posting to the Leica Users Group, 2001/06/29
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]> the entire history of twentieth century technology can be > understood as nothing more that an elaboration of nineteenth > century inventions. Only true with a very parochial focus. All communications technology is based on 20th-century work starting with Claude Shannon in 1922. In terms of the technology that allows us to talk to each other here on the LUG, I think the five most important technologies are QAM (Quadrature Amplitude Modulation) from 1953, Erbium amplifiers from 1975, packet switching (1965 or so), Winchester magnetic domain deposition (1970 or so), and the theory of directed acyclic graphs (1960's). Those enable modems, fiber optics, hard drives, internetworking, and global mesh routing. Next howabout liquid crystal (first understood in 1922, manufactured in 1960, mass-produced in 1980) or cathode ray tubes (the knowledge that electrons hitting rare earth would make light didn't happen until 1935). And though it's too soon to recognize it as a technology, the very concept of a mouse and a window and the interactive human factors that make it work took 35 years to develop to what we now all take for granted. In the 19th century nobody would even have recognized human factors as being technological. All of these technologies are based on theoretical understandings that were utterly unknown in 1901, though David Hilbert, who was alive in 1901, did much of the math that made QAM possible. Never mind that it took 50 years to invent and build the vacuum tubes and ferrite-core coils that would make it possible to test his math. The Erbium amplifier, which makes long-distance fiber possible, is based on theoretical research published for the first time in the 1960s; it is an outgrowth of laser technology, based on work by Weber and Townsend in the 1940's that was not even conceivable until a generation of scientists had used electron microscopes (1937) to study the crystallographic structure of semiconductors. Humbug Brian Reid, a 20th-century guy who is quite proud of the contributions of my century.