Your timeline (“Milestones in scientific computing” Nature 440, 399–405; 200610.1038/440399a) starts in 1946 with ENIAC, “widely thought of as the first electronic digital computer”. But that title should arguably be held by the British special-purpose computer Colossus (1943), used during the Second World War in the secret code-breaking centre at Bletchley Park.
Modern computing history starts even earlier, in 1941, with the completion of the first working program-controlled computer Z3 by Konrad Zuse in Berlin. Zuse used electrical relays to implement switches, whereas Colossus and ENIAC used tubes. But the nature of the switches is not essential — today's machines use transistors, and the future may belong to optical or other types of switches.