A brief history of black holes

I read Sabine Hossenfelder’s latest blog post yesterday. The title was A brief history of black holes. I left a couple of comments. One was a reply to Louis Marmet, and referred to Oppenheimer’s 1939 frozen star black hole. I said I think the black hole grows like a hailstone, from the inside out. The other was addressed to Hossenfelder, and referred to Einstein talking about the variable speed of light. I said that IMHO this had to mean Penrose/Hawking singularity theorems were wrong. I found…

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L-shaped contrails

Sorry I haven't posted much lately. I've been run off my feet with work. Like that woman at the end of Twelve Monkeys, I'm in insurance, and work is pressing. But anyhow, very briefly, I wanted to show you something I saw yesterday evening: L- shaped contrails. At least that's what they looked like: There appears to be two, one lower, one higher. Here's another picture I took a few seconds later: I was in Poole looking west, at circa 18:53 GMT.  Interesting, that! NEXT

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Something is rotten in the state of QED

Check out something is rotten in the state of QED. It’s a paper by Oliver Consa, who has done some excellent detective work on the history of quantum electrodynamics (QED). He has delved deep into the claims that QED is the most precise theory ever, and what he’s come up with is grim: Consa says the much-touted precision of QED is based on measurements of the electron g-factor, but that “this value was obtained using illegitimate mathematical traps, manipulations and tricks”. I think he’s right. I…

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Why clocks go slower when they’re lower

This is in response to a query from Jonas K. See my post you can lead a horse to water, and take a look at the comments. OK, I’ll start again from the beginning, Jonas, you're blue: Textbook optical clocks of the bouncing-photons-kind go slower when lower in a gravitational field, yes. So do Cesium-based atomic clocks, by exactly the same amount. Why is that? It’s because a Cesium-based atomic clock has an electromagnetic nature. Take a look at the NIST caesium fountain clock: Image courtesy…

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The theory of everything

I think when you’ve absorbed a lot of material, especially the old material, you get a handle on the theory of everything. The Einstein digital papers are important for this. That’s where you learn how gravity works. You learn that light curves because the speed of light is spatially variable. Not because it follows the curvature of spacetime. You learn that a gravitational field is a place where a space is neither homogeneous nor isotropic in a non-linear fashion. Hence when you plot your metrical measurements…

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A worble embracing itself

See the 2014 essay on the fluid dynamics of James Clerk Maxwell by Henry Keith Moffat. He referred to Maxwell’s 1867 letter to Peter Guthrie Tait. That’s where Maxwell said the simplest indivisible whorl “is either two embracing worbles or a worble embracing itself”. A worble embracing itself has a ring to it. I think it’s one of the secrets of the universe myself. Because John Williamson and Martin van der Mark were talking about something similar in their 1997 paper Is the electron a photon…

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The TOE that Maxwell missed

If you’ve ever read James Clerk Maxwell’s 1865 paper A Dynamical Theory of the Electromagnetic Field, you might have noticed his Note on the Attraction of Gravitation. It’s at the end of part IV. Maxwell ends up saying energy is essentially positive, and that “the presence of dense bodies influences the medium so as to diminish this energy wherever there is a resultant attraction”. Then he said this: “As I am unable to understand in what way a medium can possess such properties, I cannot go…

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A grand unified history lesson

Like I was saying last time, a major goal of physics is “to unify the various fundamental forces” in a theory that offers “a more elegant understanding of the organization of the universe”. This is called a grand unified theory or GUT if it doesn’t include gravity, and a theory of everything or TOE if it does: Image from Sten Odenwald’s astronomy cafe Personally I don’t understand why anybody doesn’t include gravity. Gravity is easy. Einstein explained most of it in his 1920 Leyden Address. A…

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Grand Unified Theories

I was talking to a guy the other day about Grand Unified Theories, and I thought I ought to say something about them. The Wikipedia Grand Unified Theory article gives a fair account. It says a GUT is a model where “at high energy, the three gauge interactions of the Standard Model that define the electromagnetic, weak, and strong interactions, or forces, are merged into a single force”. You’ve doubtless seen the picture: Image from the particle adventure That’s from the particle adventure website. They say this: “one of the major goals of particle physics…

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Even physicists don’t understand quantum mechanics

Check out Sean Carroll’s New York Times article Even Physicists Don’t Understand Quantum Mechanics. I thought it was great. And I just loved that subtitle: Worse, they don’t seem to want to understand it. Carroll started by quoting Feynman, who said this: “I think I can safely say that nobody really understands quantum mechanics”. That’s a good start. Feynman was known as the great explainer, but he couldn’t explain how a magnet works. Or how gravity works. Moreover he was a major contributor to quantum electrodynamics,…

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