In the next decade, another polymath, John von Neumann, at the Princeton Institute for Advanced Study, started working on an operational computer that borrowed from Turing's idea, except it would use random access memory instead of infinite tape to hold the data and operational programs. Called MANIAC (Mathematical Analyzer, Numerator, Integrator, and Computer), it was among the first modern computers ever built and was operational in 1952. MANIAC used what is now called the Von Neumann architecture, the model for all computers today.
Returning to Britain after his time at Princeton, Turing worked on another project to build a computer that used these concepts, called the Automatic Computing Engine (ACE), and pioneered the idea of a stored memory machine, which would become a vital part of the Von Neumann architecture.
As well as sparking the field of computer science, the impact his work had on cracking encryption may ultimately have also saved Great Britain from becoming a German colony. People have argued that Turing's work defining computers was essential to his success in breaking the encryption generated by Germany's Enigma machine -- work that helped bring World War II to an end.
"By today's definitions, the Enigma was an analog computer. What he [and his team] built was much closer to [the operations] of a digital computer," Rensselaer's Hendler explained. "Essentially he showed the power of digital computing in attacking this analog problem. This really changed the whole way that the field thought about what computers could do."
Having defined computational operations, Turing went on to play a fundamental role in defining artificial intelligence -- or computer intelligence that mimics human thinking. In 1950, he authored a paper that offered a way to determine if a computer possessed human intelligence. The test involves a person having an extended conversation with two hidden entities, a computer and a man pretending to be a woman. ("In both cases he wanted pretending," Hendler explained.) If the person can't determine which party is the computer, the machine can be said to think like a human.
"He wanted to put human and computing on equal footing," Hendler said. "Language is a critical skill for humans because it requires understanding and context. If a computer showed that level of understanding then you wouldn't notice the difference."
The test "has the advantage of drawing a fairly sharp line between the physical and the intellectual capacities of a man," Turing wrote in the original paper.