(L)earning (C)ritical (T)hinking (T)hrough (A)stronomy. Colorful and coordinate-free. I inhabit the cotangent space. Independent Scholar Working in Private Practice (ISWPP). AAPT Fellow. I maintain the mandi LaTeX package. I think all intro physics courses should include special and general relativity. Thirty years of physics and astronomy teaching experience. TeX/LaTeX/Python/VPython/WebVPython/SymPy/Overleaf
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2026-04-08T10:19:10Z Event JSON
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Last Notes npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…60xv Why does Vivaldi frequently mangle the names of files I download? I just downloaded a new version of Stellarium and the file Stellarium-26.1-qt6-macOS.zip turned into 329812a5-c06f-4145-b30c-f07301061876 upon downloading. This only happens with Vivaldi. Any suggestions? macOS 26.4 with very latest Vivaldi. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…ztfm I hope users leave in droves. The site is horrible enough already but maybe this will finally kill it off. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Holy crap! @nprofile…pza5 fixed a bug in the iOS app that I reported! (The bug was that the Search bar wasn't working for Saved articles.) Thanks guys! npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Okay. Just met Sean M. Carroll. *squeee* npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…5k3r This book is AMAZING and no one seems to know much of anything about Kevin Brown. The diagrams on pages 330 and 331 (first edition) showing contravariant and covariant components was the first time I ever saw that distinction and thus was the first time those concepts made any sense to me. The new book by Antony Musker references the diagram and builds an exercise around it. I think it’s a didactically significant diagram! A second edition of Brown is out now. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…args You caused me to learn how to block specific search results, which I didn't even know was possible. Many thanks! npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner I just discovered bookshop.org. Have you tried them yet? #Books npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Introducing someone, indeed anyone, to a new body of knowledge should be considered an honor. You may very well form their attitude towards that body of knowledge and they will reflect that when their time comes to decide on further study or research. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…typy Will f-strings go away? npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…uk4z Clams are interesting as hell! npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…x9jw Is the History icon in the vertical toolbar (is that its name?) supposed to change? It looks different than it did yesterday for some reason. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner I’m only 20 pages into A Geometrical Introduction to Tensor Calculus by Jeroen Tromp (Oxford U. Press, 2025) and I’m already enlightened. Tromp is a geophysicist specializing in seismology and this book is thus far great at connecting the mathematician’s world with the physicist’s world. #ITeachPhysics #ITeachMath #TensorCalculus npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…5k3r This is a pretty good channel. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @nprofile…48vs Academic administrators are quite fond of labeling any pushback as “uncivil” and “insubordinate.” npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @npub1zdp…vqv8 My Sheldon can open the bedroom door when it’s closed. No idea how he does it. Nearly gave me a heart attack the first time he did it in the dead of night. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Colleagues: “How can you talk like that without getting fired?” npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @npub15c0…hxke Vivaldi running on macOS Sonoma on my M1 iMac simply will not download my backup encryption key to my local drive. I can do so on my Intel MBP. I have checked for permissions but see nothing wrong. Any suggestions? npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner I don’t mind photons, but I just wish there were fewer of them in the morning. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner I’ve been yak shaving all my life and only today did I know it has a name. H/t to @npub1c9m…9xjd. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @npub12jq…0xvr Same. Tenth grade…1982/1983…geometry class. I wrote a program to compute the midpoint of a line segment given the coordinates of the endpoints. I was hooked. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Just saw a former coworker who’s still at my former place. As I predicted years ago, administration has officially disbanded the Faculty Senate leaving faculty without a voice. Where’s the accreditor when things like this happen? I sounded so many alarms while I was there but no one cared and no one listened. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner I wish Apple would take just one year off and fix things instead of breaking more things. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner Theorem: Face any random direction. Walk x meters, where x is a real number whose minimum value varies with the day, and you will encounter an elitist. Proof by everyday experience. QED. npub1rm94exvdka03xpkhst57d7llxdz70nptvu6unhfa04plr24euqzs73w3zm Joe Heafner @npub15c0…hxke What’s up with Amazon challenging me with a captcha when I enter their URL? This has only been happening with Firefox but it happened just now with Vivaldi. Any ideas?
