Machines That Think! (Big Ideas That Changed the World #2)

Gr 3-7--Brown continues his "Big Ideas That Changed the World" series with a look at machines through the ages. Ancient mathematician Muhammad ibn-Mu̅sa̅ al-Khwa̅rizmi̅ offers readers a primer on technology, from the abacus to 16th-century thinker Blaise Pascal's Pascaline ("a shoebox-sized gadget that used gears, wheels, axles, and dials to add numbers") to Ada Lovelace's analytical machine to the early computers used by NASA, and, finally, to smartphones. As in Rocket to the Moon, Brown adeptly explains how scientists and thinkers stand on the shoulders of giants, each building upon earlier technology and advancing knowledge. The narrative is quick and engaging, accompanied by Brown's familiar watercolors. Expressive characters, visual humor, and details that will reward careful readers, along with asides from al-Khwa̅rizmi̅ ("Not bad for a self-taught engineer!"), infuse this informative work with wit and verve. Those left wanting more will appreciate the time line, notes about binary code, and the thorough bibliography. VERDICT Accessible, occasionally funny, and always thoughtful, this speedy but thorough trip through time is a must for budding scientists.--Jody Kopple, Shady Hill School, Cambridge, MA