This is somewhat technical. It's for those interested in the puzzle of how we get the irreversible processes we see all around us from laws that are supposedly reversible. The trick: they are not all reversible. A crucial part of the physics of Nature involves an irreversible step that has long been neglected. The paper … Continue reading More on Entropy and the Arrow of Time →

“By final [state], we mean at that moment the probability is desired—that is, when the experiment is “finished.” –Richard P. Feynman, Feynman Lectures, Vol. 3 The challenge of defining measurement is evident in the excerpt from Feynman’s famous Lectures in Physics, quoted above--when is the experiment 'finished'??. This remark arises in his discussion of when … Continue reading Observation is Measurement, but Measurement is not necessarily “Observation” →