That's quite wrong about Unix. http://www.cs.bell-labs.com/who/dmr/hist.html http://www.cs.bell-labs.com/who/dmr/hist.html I can't speak as confidently about t

That's quite wrong about Unix. http://www.cs.bell-labs.com/who/dmr/hist.html http://www.cs.bell-labs.com/who/dmr/hist.html I can't speak as confidently about the rest, but the impression I get is that people like Gauss were hacking up telegraphs very soon after enough basic components and knowledge were in place; i.e. the gating factor was not the need for better communications but the new knowledge out of left field. Likewise the CRT seems motivated by curiosity more than technological problem-solving: http://en.wikipedia.org/wiki/Cathode_ray#History http://en.wikipedia.org/wiki/Cathode_ray#History The Bell Labs transistor seems to fit your model, though I wonder about the Lilienfield patent 20 years earlier: http://en.wikipedia.org/wiki/History_of_the_transistor http://en.wikipedia.org/wiki/History_of_the_transistor "Invention is the mother of necessity" looks like a better fit for most of these examples.