Imagine a grain of fine beach sand. What’s its size? Classification scales vary, but let’s say less than a tenth (0.1) of a millmeter (mm). A grain of table salt. Same question. Maybe ~0.3 mm. In either grain there are a gazillion molecules. Now imagine something a thousand (1000) times smaller – a micrometer-sized grain.… Continue reading Tiny grains tell a stellar story
Ask people on the street “What are X-rays?” and you’ll likely get a variety of replies. About medical and dental X-rays. Stories about Superman’s X-ray vision. (Why does lead block X-rays?) Invisible particles that allow us to see through stuff. Technical explanations about electromagnetic radiation. So, street surveys typically reveal levels of understanding, which I’ll… Continue reading Levels of understanding – what are X-rays?
[“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?
You’ve probably heard the saying, “We will sell no wine before its time.” While most of us rarely think about the topic when buying retail wines, the more adventurous might go for age-worthy bottles – immature wines which can taste quite better at their peak. How long do you wait? Is there a mathematical model for… Continue reading Wine before time itself – stars older than the universe?
Yesterday the buzz started about the announcement of the 2019 Nobel Prize in physics. Here’re some samples of articles on the joint award to three scientists. A testimony to research on the cosmic microwave background radiation (and understanding of the universe’s evolution) and advances in observational astronomy. • Washington Post > “Nobel Prize in physics… Continue reading 2019 Nobel Prize in physics — our place in the universe
[“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
I generally get the difference between matter particles (leptons and quarks) and “force carrying” particles (bosons). But I still do not understand how the “exchange” of fundamental / elementary bosons (e.g., photons and gluons) bind or ‘glue’ matter particles together as well as repel matter particles — as in attraction of oppositely charged particles and… Continue reading A boson by any other name would …
[Topic placeholder] [Developing story] Today’s news cycle contains articles about research by some physicists at the University of Glasgow who claim to have imaged entangled photons. Looks like they used a precision laser-based, table-top optical bench system. This Cnet article is a basic summary of the research: “Einstein called it ‘spooky action.’ Here’s an image… Continue reading Image of entangled photons?
Before encountering this Quanta Magazine article today, I’d not heard of this aspect of quantum measurement theory: “The Quantum Theory That Peels Away the Mystery of Measurement” (July 3, 2019) by Philip Ball, Contributing Writer (author of Beyond Weird: Why everything you thought you knew about quantum physics is different). Well, a quick Google search… Continue reading Quantum trajectory theory?
[“Models of the quantum vacuum” series] I read this article today “‘The Unknown Question’ — The End of Spacetime” (June 22, 2019) and watched the included YouTube videos. Something bothered me which I’ve been thinking about for years, namely, that even theoretical physicist Nima Arkani-Hamed sounded like he viewed the electron as like a spherical… Continue reading Swaying quantum vacuum energy vs compelling charge