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Jordana Cepelewicz on a very different approach to computing…

In 1936, the British mathematician Alan Turing came up with an idea for a universal computer. It was a simple device: an infinite strip of tape covered in zeros and ones, together with a machine that could move back and forth along the tape, changing zeros to ones and vice versa according to some set of rules. He showed that such a device could be used to perform any computation.

Turing did not intend for his idea to be practical for solving problems. Rather, it offered an invaluable way to explore the nature of computation and its limits. In the decades since that seminal idea, mathematicians have racked up a list of even less practical computing schemes. Games like Minesweeper or Magic: The Gathering could, in principle, be used as general-purpose computers. So could so-called cellular automata like John Conway’s Game of Life, a set of rules for evolving black and white squares on a two-dimensional grid.

In September 2023, Inna Zakharevich of Cornell University and Thomas Hull of Franklin & Marshall College showed that anything that can be computed can be computed by folding paper. They proved that origami is “Turing complete” — meaning that, like a Turing machine, it can solve any tractable computational problem, given enough time…

Read on for more on how folding paper can, in principle, be used to perform any possible computation: “How to Build an Origami Computer” from @jordanacep in @QuantaMagazine.

* Jon Franklin

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As we contemplate calculation, we might send entropic birthday greeting to Rolf Landauer; he was born on this date in 1927. A physicist, we made important contributions made important contributions in several areas of the thermodynamics of information processing, condensed matter physics, and the conductivity of disordered media… most of which important to the development of computing (of the electronic variety).

He is best known for his discovery and formulation of what’s known as Landauer’s principle: that in any logically irreversible operation that manipulates information, such as erasing a bit of memory, entropy increases and an associated amount of energy is dissipated as heat– a “thermodynamic cost of forgetting,” relevant to chip design (how closely packed elements can be on a chip and still handle the heat), reversible computing, quantum information, and quantum computing… but not an issue for origami.) 

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