A Digital Universe

A digital universe – whether 5 kilobytes or the entire Internet – consists of two species of bits: differences in space, and differences in time. Digital computers translate between these two forms of information – structure and sequence – according to definite rules. Bits that are embodied as structure (varying in space, invariant across time) we perceive as memory, and bits that are embodied as sequence (varying in time, invariant across space) we perceive as code. Gates are the intersections where bits span both worlds at the moments of transition from one instant to the next.

– George Dyson, from Turing’s Cathedral

George Dyson / Turing’s Cathedral: the origins of the digital universe

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The Four Basic Electronic Components

A fourfold has recently been in the news. The physical realization of the memristor completes the four basic electronic components, along with the resistor, capacitor, and inductor. Theorized to exist since 1971, the memristor may revolutionize computational devices.

http://en.wikipedia.org/wiki/Memristor

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The Duality of Time and Information

The states of a computing system bear information and change time, while its events bear time and change information.

– from The Duality of Time and Information by Vaughn Pratt

The most promising transformational logic seems to us to be Girard’s linear logic.

– from Rational Mechanics and Natural Mathematics by Vaughn Pratt

Vaughan Pratt / The Duality of Time and Information http://boole.stanford.edu/pub/dti.pdf

Vaughan Pratt / Time and Information in Sequential and Concurrent Computation http://boole.stanford.edu/pub/tppp.pdf

Vaughan Pratt / Rational Mechanics and Natural Mathematics http://chu.stanford.edu/guide.html#ratmech