arXiv subjects

Alan Forrester

Publications and source records attributed to Alan Forrester.

3 recordsLinked to original sources

arXiv2011

Reality is both digital and analog

I argue that both digital and analog information are important in the foundations of quantum physics. If it is possible for information present in one system to become present in others without being erased in the original system I will say that this information can be copied. I argue that copying is important for understanding issues like causality and that all information that can be copied is digital. I then explain that analog information that cannot be copied can be understood in terms of decision theoretic probability. Finally, I argue that these ideas can help explain the second law of thermodynamics. The arrow of time we experience is the knowledge arrow of time -- the present contains more knowledge, that is, useful or explanatory information, than the past. That knowledge is created by evolutionary processes that involve copying, variation and selection and such processes increase entropy.

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arXiv2008

Growth of Knowledge and Entropy in Quantum Physics

Most attempts to argue for the second law of thermodynamics fail because (1) they use the unviable frequency theory of probability and (2) they do not explain why the arrow of time seen in experiments is aligned with the thermodynamic arrow of time. I use the decision theoretic interpretation of quantum probability from the many worlds interpretation of quantum mechanics to solve the probability problem. I then derive a correlation between the knowledge arrow of time and the entropy arrow of time using physical constraints on knowledge creation imposed by Popper's evolutionary theory of knowledge and the many worlds interpretation.

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arXiv2007

Decision theory and information propagation in quantum physics

In recent papers, Zurek has objected to the decision-theoretic approach of Deutsch and Wallace to deriving the Born rule for quantum probabilities on the grounds that it courts circularity. Deutsch and Wallace assume that the many worlds theory is true and that decoherence gives rise to a preferred basis. However, decoherence arguments use the reduced density matrix, which relies upon the partial trace and hence upon the Born Rule for its validity. Using the Heisenberg Picture and quantum Darwinism - the notion that classical information is quantum information that can proliferate in the environment pioneered by Olliver et al - I show that measurement interactions between two systems only create correlations between a specific set of commuting observables of system 1 and a specific set of commuting observables of system 2. This argument picks out a unique basis in which information flows in the correlations between those sets of commuting observables. I then derive the Born rule for both pure and mixed states and answer some other criticisms of the decision theoretic approach to quantum probability.

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