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Mathematics

The Universal Turing Machine and Computational Universality

Quick fact

In 1936, Alan Turing described a 'universal machine' that could read the description of any other Turing machine and then mimic its behavior. This single, fixed device can perform any computation that any computer could ever perform, which is why it underlies the theoretical foundation of all general-purpose computers.

Why this is interesting

You probably own a powerful computer, but have you ever wondered how a single machine can run a word processor, a game, or a spreadsheet—all just by loading different software? The answer lies in a concept from 1936: a machine that can simulate every other machine.