Physics, Topology, Logic and Computation: A Rosetta Stone by John C. Baez and Mike Stay, 2009.

In physics, Feynman diagrams are used to reason about quantum processes. In the 1980s, it became clear

that underlying these diagrams is a powerful analogy between quantum physics and topology. Namely, a linear

operator behaves very much like a `cobordism': a manifold representing spacetime, going between two

manifolds representing space. This led to a burst of work on topological quantum field theory and `quantum

topology'. But this was just the beginning: similar diagrams can be used to reason about logic, where

they represent proofs, and computation, where they represent programs. With the rise of interest in quantum

cryptography and quantum computation, it became clear that there is extensive network of analogies between

physics, topology, logic and computation. In this expository paper, we make some of these analogies precise

using the concept of `closed symmetric monoidal category'. We assume no prior knowledge of category

theory, proof theory or computer science.

I am not sure whether this should be categorized as "Fun" instead of "Theory", given that "We assume no prior knowledge of category theory, proof theory or computer science".

At least one pair from the title (logic and computation) should ring some bells...

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