[“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
In the last few months, I’ve been struck by how many articles have been published in the popular media and science news about black holes and the Big Bang. Mainstream physics and science communications (like phys.org, quantamagazine.org, etc) lately seem to be discussing more and more “mind blowing” geometries of the universe (or multiverse, eh).… Continue reading Cosmological fact and fiction
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?
A trip down memory lane this week led me to the topic of this post. In exchanging emails with a fellow alumnus, I mentioned the book A Canticle for Leibowitz1 which we read in a freshman English class. He remembered the professor’s name. That led to an exploration of my file cabinets and the class… Continue reading Two cultures redux
Earth Day April 22, 2017 The March for Science is the first step of a global movement to defend the vital role science plays in our health, safety, economies, and governments. Here’s the page for locations in California. And the page for the Los Angeles event: MARCH FOR SCIENCE LOS ANGELES CELEBRATES THE CRUCIAL ROLES SCIENCE PLAYS… Continue reading March for science
In the chapter “Beyond this horizon,” Sean Carroll discusses two related problems involving properties of empty space. Before discussing the vacuum energy problem, he profiles the so-called hierarchy problem in the cosmic energy scale. It’s about the effects of virtual particles. The energy scale that characterizes the weak interactions (the Higgs field value, 246 GeV)… Continue reading Sisyphean hierarchy
[“Models of the quantum vacuum” series] A theoretical physicist walks into a bar. The bartender says, “What can I get you?” The physicist says, “Nothing.” The bartender gives the physicist an empty glass. The physicist says, “Thanks, that’s plenty!” Physicists take emptiness quite seriously. So-called empty space is an important area of study and research.… Continue reading Empty dumpty
Here’s my take on gauge symmetry after reading about the concept (some references are listed below). There are mathematical frameworks for space, and in physics there are equations of motion for space. A mathematical framework deals with geometric and numeric objects. In everyday life we basically equate these objects with a Euclidean space using the… Continue reading Symmetry → connection field → force of nature