[Draft] If space-time is considered as a kind of material, then what properties make sense? Properties that can be observed, measured. In the context of General relativity, (aggregate) properties related to curvature and rippling. Like elasticity, stiffness. In the context of quantum physics, (discrete) properties related to quanta, energy density, charge, spin, entanglement. Like gradients,… Continue reading How stiff is space-time?
[“Quantum foundations” series] Carlo Rovelli’s new book Helgoland – Making Sense of the Quantum Revolution is in the news cycle this week, with promo’s and reviews. (Probably more comments later.) (quote) Helgoland is a book by Italian physicist Carlo Rovelli. It is about quantum mechanics and its relational interpretation. The title refers to Werner Heisenberg’s… Continue reading Helgoland? – escape from quantum island
[“Quantum foundations” series] A physicist walks into a bar, and asks the bartender, “What time is it?” The bartender is about to reply but then recognizes the customer. “You’re a physicist, correct? So, it’s a trick question.” So, what’s with time? A venerable philosophical question. A foundational question in physics. We have electronic devices, extremely… Continue reading Whence the arrow of time?