The quantum computer is here.   Transition : The earliest intelligent life might have used fingers to compute. The Lebombo bone, dating back 35,000 BC, had 29 distinct notches. The Sumerian abacus appeared around 2500 BC.  China only used this device around the year zero. Several analog computers go back to around 150 BC in Greece with the astrolabe. In 1206 came the first programmable computer, a clock. Soon thereafter, the  equatorium .  Here is one by Johannes Schoner in the 16th century. The slide rule was invented around 1620 in England. Germany designed the first calculating machine in 1623. In 1645 Blaise Pascal invented a mechanical calculator. Gottfried von Leibniz dabbled with a binary numeral system around 1675, the means by which all modern computers now work. In 1822 Charles Babbage's machines used the decimal system, and so did ENIAC in 1945. When I taught computer programming half a century ago, I used punched cards, something invented in 1804 by ...