Posts Tagged ‘Rolf Landauer’
“Simplicity, carried to the extreme, becomes elegance”*…
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.)
“Visualization gives you answers to questions you didn’t know you had”*…
Physical representations of data have existed for thousands of years. The List of Physical Visualizations (and the accompanying Gallery) collect illustrative examples, e.g…
5500 BC – Mesopotamian Clay Tokens
The earliest data visualizations were likely physical: built by arranging stones or pebbles, and later, clay tokens. According to an eminent archaeologist (Schmandt-Besserat, 1999):
“Whereas words consist of immaterial sounds, the tokens were concrete, solid, tangible artifacts, which could be handled, arranged and rearranged at will. For instance, the tokens could be ordered in special columns according to types of merchandise, entries and expenditures; donors or recipients. The token system thus encouraged manipulating data by abstracting all possible variables. (Harth 1983. 19) […] No doubt patterning, the presentation of data in a particular configuration, was developed to highlight special items (Luria 1976. 20).”
Clay tokens suggest that physical objects were used to externalize information, support visual thinking and enhance cognition way before paper and writing were invented…
There are 370 entries (so far). Browse them at List of Physical Visualizations (@dataphys)
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As we celebrate the concrete, we might carefully-calculated birthday greetings to Rolf Landauer; he was born on this date in 1927. A physicist, he made a number important contributions in a range of areas: the thermodynamics of information processing, condensed matter physics, and the conductivity of disordered media.
He is probably best remembered for “Landauer’s Principle,” which described the energy used during a computer’s operation. Whenever the machine is resetting for another computation, bits are flushed from the computer’s memory, and in that electronic operation, a certain amount of energy is lost (a simple logical consequence of the second law of thermodynamics). Thus, when information is erased, there is an inevitable “thermodynamic cost of forgetting,” which governs the development of more energy-efficient computers. The maximum entropy of a bounded physical system is finite– so while most engineers dealt with practical limitations of compacting ever more circuitry onto tiny chips, Landauer considered the theoretical limit: if technology improved indefinitely, how soon will it run into the insuperable barriers set by nature?
A so-called logically reversible computation, in which no information is erased, may in principle be carried out without releasing any heat. This has led to considerable interest in the study of reversible computing. Indeed, without reversible computing, increases in the number of computations per joule of energy dissipated must eventually come to a halt. If Koomey‘s law continues to hold, the limit implied by Landauer’s principle would be reached around the year 2050.
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