[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?
Frank Wilczek referenced this topic – time crystals – in his latest book (Fundamentals: Ten Keys to Reality). Time crystals are physical systems that spontaneously settle into stable loops of behavior. I proposed this concept in 2012, and many interesting examples have been discovered since then, both theoretically and experimentally. A recent example is close to… Continue reading Time crystals? – crystal patterns in space and time
So, the short answer is yes. A useful model, at a certain scale. How can that be? The cosmos is full of stuff. Vast collections of stars, planets, rocks, dust, gas. Chunked over vast distances. Not what our everyday experience considers fluid stuff. Well, in physics and engineering, fluid dynamics embraces what typically are referred… Continue reading The cosmos is like a fluid?
So, what are axions? I’ve noticed more articles lately about axions. Why all the fuss, eh? • Wiki The axion is a hypothetical elementary particle postulated by the Peccei–Quinn theory in 1977 to resolve the strong CP problem [violation of the combined symmetries of charge conjugation and parity] in quantum chromodynamics (QCD). If axions exist… Continue reading What are axions – real or not?
I read more articles this past week about research on the proton. Some refined measurements. Some better insights into topics in quantum theory. Rather than add comments to related posts, I decided that a new post was appropriate. It struck me that the proton, as a composite particle (“particle” in the sense of an excitation… Continue reading Proton soup – a turbulent, dynamically complicated structure