[“Quantum foundations” series] I encountered a Wired reprint of a Quanta Magazine article which I’d flagged awhile ago; so, it’s time to write a new post. While reconciling Quantum Theory and General Relativity is an ongoing topic, I found this Quanta Magazine article interesting for its discussion of unitarity and Hilbert space. Although based on… Continue reading Unitarity forever? – in an expanding universe
[Draft] [“Beyond the Standard Model” series] Background on the “crisis” This Quanta Magazine article (below) has an eye-catching title, but its gist relates to the hierarchy problem, which I discussed in a prior post. That 2017 post (and additionaL commentary) used quotes by physicists – Sean Carroll, Leon Lederman, Fermilab’s Don Lincoln (video) – and… Continue reading Reductionism in quantum physics – a naturalness mire?
[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] Demons in physics? Well, historically as fanciful ways to explore theories using skilled marvels – an illuminating rather than malevolent context. Pure imagination, not imagineering, eh. Physicist James Clerk Maxwell created a thought experiment in 1867. His idea involved a fantastical “finite being” able to sort molecules of a gas. Rarified acuity… Continue reading Laplace’s demon RIP? – demons of physics
[“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?
[“Quantum foundations” series] [Updated December 2019] Introduction to this topic If Murray Gell-Mann was right that Niels Bohr brainwashed a generation of physicists to accept the Copenhagen Interpretation, either his influence has waned or he didn’t do a very good job in the first place. For in an informal poll conducted at an international meeting… Continue reading Quantum reality, quantum worlds – new book explores quantum foundations
Much has been written about Richard Feynman. Many tributes and books. Feynman wrote some books as well. But the inspiration for this post is an exhibit promoted for Caltech’s 82nd Annual Seminar Day and Reunion Weekend May 16 – 19, 2019. The Mind’s Eye: Richard Feynman in Word & ImageIn work and play, Richard Feynman… Continue reading Feynman’s legacy — quantum originality
Stephen Hawking died last week. Lots of tributes in the media about his scientific legacy and life. Sean Carroll posted an article on his blog on March 16: “Stephen Hawking’s Scientific Legacy.” It’s particularly interesting. As a career physicist and cosmologist, Carroll met and interacted with Hawking over the decades. Early in his career Carroll turned… Continue reading Celebrity and cultural phenomenon — Stephen Hawking
Perhaps the ultimate why question: Why is there something rather than nothing? Sean Carroll’s blog is a feed on my blog. I enjoyed reading his recent post and paper on this question. Quite a challenge to summarize the topic in 15 pages. I’ve talked before about the issue of why the universe exists at all… Continue reading Ultimate why?
