That is, a machine that reads an arbitrary Turing machine description from a tape and simulates it. You can argue that such a machine forms the basis for the modern stored-program computer.

Scientists have created the first “chemical Turing machine,” meaning a liquid that can do the calculations that define a classic computer science standard.

Turing completeness in blockchain allows for universal computation, enabling diverse applications and smart contracts with limitless computational possibilities.

As Ian Bogost wrote last year on this website, the same concept drives Turing’s other great contribution to computer science—the universal computing machine.