Hannah Earley

My name is Hannah Amelie Earley. I am a newly-qualified researcher working on forms of unconventional computing, with a special interest in reversible and molecular computing. My research centers on the physics and computer science of abstract forms of these systems, whilst my future directions will expand into their practical implementation. My PhD was completed under the supervision of Gos Micklem and based in Cambridge


on the performance and programming of reversible molecular computers

My thesis comprised the following two projects, ‘engines of parsimony’ and ‘the ℵ calculus’.


engines of parsimony

This project focuses on the maximum rate of computation that can be achieved by any physical computer within a given region of space and provided a given supply of power and rate of heat dissipation. In part i, we find general scaling laws independent of whether the computers are quantum or classical, and also find how these depend on whether the computers are reversible or irreversible. We also extend to the cases of very small and very large computers. In parts ii and iii, we consider the consequences of this performance maximisation on cooperative/concurrent reversible computers from the perspectives of communication and resource sharing respectively.

when general relativistic effects such as gravitational collapse become important

the ℵ calculus

Inspired by the recommendation of reversible computing obtained in engines of parsimony, we developed a model of computation—the ℵ calculus—and an associated programming language—alethe—for declarative reversible computation. Being declarative, it is amenable to composition and high level programming. Other select features include automatic parallelisation, and explicit but intuitive separation of effects from 'pure' code. What we feel is most novel about ℵ is that it models the reversibility of not just the transformation of data, but also the program state itself. This makes it a good model for building physical reversible computers. In particular it is well suited for molecular implementations, and supports interaction and communication between non-local computational entities.




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