Witness gravity's quantum side in the lab.
Nature Nature Research 547:7662 (2017) 156-158
Beyond Initial Conditions and Laws of Motion: Constructor Theory of Information and Life
Chapter in From Matter to Life, Cambridge University Press (CUP) (2017) 38-58
Evolution without evolution and without ambiguities
Physical Review D American Physical Society 95:4 (2017) 043510
Abstract:
In quantum theory it is possible to explain time, and dynamics, in terms of entanglement. This is the timeless approach to time, which assumes that the universe is in a stationary state, where two noninteracting subsystems, the "clock" and the "rest," are entangled. As a consequence, by choosing a suitable observable of the clock, the relative state of the rest of the universe evolves unitarily with respect to the variable labeling the clock observable's eigenstates, which is then interpreted as time. This model for an "evolution without evolution" (Page and Wootters, 1983), albeit elegant, has never been developed further, because it was criticized for generating severe ambiguities in the dynamics of the rest of the universe. In this paper we show that there are no such ambiguities; we also update the model, making it amenable to possible new applications.Constructor Theory of Information
Chapter in Information and Interaction, Springer Nature (2017) 103-111