Genius Week continues here at OPOD with our next selection . . . Jack Kilby. Yesterday we explained that the transistor was invented by Schockley and his cohorts. The transistor enabled things like the portable radio. In the 1920's-1940's, radios were big power hungry behemoths, but with the invention of the transistor, by the 1950's and 1960's you could have a portable battery powered radio you could carry around in your pocket. At this time, transistors were still built one at a time, and then wired up to make things like radios or radars. The genious of Jack Kilby was that he thought, " Hey, why build transistors one at a time . . . why not build a bunch at the same time and batch fabricate the circuits in bulk all on the same piece of silicon". This building of lots of interconnected transistors at the same time on the same piece of silicon is the Integrated Circuit. This is what allowed things like the pocket calculator which came on the scene in the early 1970's.