So, regarding interaction of matter, there’s a major inversion of perspective between classical physics and quantum field theory (QFT): hallmarked particles which create fields vs. excitations created (and destroyed) in ubiquitous extant fields. As Ethan Siegel said: … in quantum field theory, quantum fields aren’t generated by matter. Instead, what we interpret as “matter” is… Continue reading Equal footing in quantum physics
[“Building a ‘verse” series] Ever since I started reading about Quantum Field Theory (QFT), I was interested in how physicists talk about fields. And the multiplicity of fields. And how quantum fields compare to classical fields. So, as I’ve written elsewhere, the basic notion is that every matter particle is an excitation (or localized vibration)… Continue reading QFT – How many fields are there?
Today’s post is somewhat different than usual. I’m highlighting a YouTube channel. Communicating science to a general audience has a long history. The bibliography for my physics blog contains some books by authors to this purpose. Modern physics has many great stories, and the just plain strangeness of quantum physics lends itself to great storytelling.… Continue reading Communicating what physics says — The Science Asylum
While studying physics this past year, I noticed tension between theoretical and experimental physicists, especially between younger quantum field theoreticians and veteran particle physicists — regarding deep reality and the various formulations of quantum mechanics (addressed in another post). Revisiting some archived debates, this philosophical question (“Is reality digital or analog?”) was posed in an essay… Continue reading Is reality digital or analog?
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
[A creative writing exercise] The other day I was glad to see that I was far from alone in my puzzlement about how the so-called exchange of bosons (as “force carriers”) produces both repulsion and attraction. Modeled in classical mechanics as particles; in Quantum Field Theory (QFT) as gauge boson fields — force fields. In… Continue reading Virtual attraction
So, here’s the thing. If I roll with Quantum Field Theory (QFT), how do I reconcile my macroscopic and microscopic views of things. Simple things. Like looking at a tiny candle across the room? “P vision” Imagine if we could see individual photons (without being overwhelmed by visual “noise” in very low light). Where might… Continue reading Beyond frog vision
Happy Pi Day! When you’re trying to solve any interesting problem (a problem about almost anything) — a problem with lots of interplay between different things, it’s important to know what’s important and not, what makes a big effect on the result and not. And just how precise the result needs to be anyway (at… Continue reading Effective theory
Physics was a requirement for the first two years when I was an undergrad. That introduced me to The Feynman Lectures on Physics, three heavy red volumes (© 1963, 1964, 1965). The preface in each volume had a picture of Feynman playing the bongo drums. And then the early morning physics labs. Two of the… Continue reading Reality is fields
One of the major sources of confusion I’ve encountered in reading about modern physics is the discussion of gravity. No surprise, eh. Classical mechanics includes both Newtonian and relativistic mechanics. In Newtonian physics, gravity is an attractive force, which acts at a distance between all objects; and can be represented as a universal gravitational field.… Continue reading GR: Chicken or egg redux
