Andrew J. Steinmetz
@ajsteinmetz.com
Physics PhD, fmr. Global Professor at the University of Arizona. Talks about physics, astronomy and other sciences! (views my own) ⚛️🔭🧪🧮 https://ajsteinmetz.github.io/
New #Protomen! I'm so thrilled to post each and every drop until #ActIII is fully out. theprotomen.bandcamp.com/track/hold-o...
November 4, 2025 at 10:41 PM
New #Protomen! I'm so thrilled to post each and every drop until #ActIII is fully out. theprotomen.bandcamp.com/track/hold-o...
It turns out you can order free hard copies of the NRL Plasma Formulary book from the US Navy. www.nrl.navy.mil/News-Media/P...
The PDF is also freely available.
Making my tax dollars work lol. Though with the shutdown, I don't know if they'll respond. #Physics #Science 🧪⚛️
The PDF is also freely available.
Making my tax dollars work lol. Though with the shutdown, I don't know if they'll respond. #Physics #Science 🧪⚛️
October 31, 2025 at 4:00 PM
It turns out you can order free hard copies of the NRL Plasma Formulary book from the US Navy. www.nrl.navy.mil/News-Media/P...
The PDF is also freely available.
Making my tax dollars work lol. Though with the shutdown, I don't know if they'll respond. #Physics #Science 🧪⚛️
The PDF is also freely available.
Making my tax dollars work lol. Though with the shutdown, I don't know if they'll respond. #Physics #Science 🧪⚛️
#TIL the mathematician #Fibonacci (b. 1170) was one of the early promoters of the Indo-Arabic numeral system in Europe in his 13th century book Liber Abaci where he also printed the now famous Fibonacci sequence 1, 2, 3, 5, 8, 13, ... as a solution to the "rabbit problem." #Science #MathSky 🧪🧮
October 29, 2025 at 4:44 PM
#TIL the mathematician #Fibonacci (b. 1170) was one of the early promoters of the Indo-Arabic numeral system in Europe in his 13th century book Liber Abaci where he also printed the now famous Fibonacci sequence 1, 2, 3, 5, 8, 13, ... as a solution to the "rabbit problem." #Science #MathSky 🧪🧮
This City Made Us! #Protomen #Music #RockOpera Act III drops continue with this rerelease of the 2015 EP song.
theprotomen.bandcamp.com/track/this-c...
theprotomen.bandcamp.com/track/this-c...
October 29, 2025 at 2:07 AM
This City Made Us! #Protomen #Music #RockOpera Act III drops continue with this rerelease of the 2015 EP song.
theprotomen.bandcamp.com/track/this-c...
theprotomen.bandcamp.com/track/this-c...
October 26, 2025 at 3:38 PM
Now here's an example of one of the more useful applications of #AI and #MachineLearning within #Medicine. AI-assisted doctors are significantly better at detecting breast cancers in women. This kind of usage directly saves people's lives. #Science #MedSky 🧪💊
Source: doi.org/10.1038/s415...
Source: doi.org/10.1038/s415...
October 25, 2025 at 5:15 PM
Now here's an example of one of the more useful applications of #AI and #MachineLearning within #Medicine. AI-assisted doctors are significantly better at detecting breast cancers in women. This kind of usage directly saves people's lives. #Science #MedSky 🧪💊
Source: doi.org/10.1038/s415...
Source: doi.org/10.1038/s415...
I recently gave a presentation on #AI which covered in-part the dangers of over-reliance in #Medicine. While lots of attention is on #Education, with good reason, even experts are at risk of "deskilling." #AcademicSky #Science #MedSky 🧪💊
Source: doi.org/10.1016/s246...
Source: doi.org/10.1016/s246...
October 25, 2025 at 1:27 AM
I recently gave a presentation on #AI which covered in-part the dangers of over-reliance in #Medicine. While lots of attention is on #Education, with good reason, even experts are at risk of "deskilling." #AcademicSky #Science #MedSky 🧪💊
Source: doi.org/10.1016/s246...
Source: doi.org/10.1016/s246...
I won't stop #Protomen posting until Act III is fully out and dropped. Calling Out is a great song. #Music #RockOpera
youtu.be/z2Wh3hq2EPQ?...
youtu.be/z2Wh3hq2EPQ?...
October 23, 2025 at 10:12 PM
I won't stop #Protomen posting until Act III is fully out and dropped. Calling Out is a great song. #Music #RockOpera
youtu.be/z2Wh3hq2EPQ?...
youtu.be/z2Wh3hq2EPQ?...
More Act III posting. Today's juice is The Storm and Buried in the Red! Continue the new songs #Protomen! #Music #RockOpera #ConceptAlbum.
October 14, 2025 at 5:24 PM
More Act III posting. Today's juice is The Storm and Buried in the Red! Continue the new songs #Protomen! #Music #RockOpera #ConceptAlbum.
Second week of new songs for the #Protomen final album Act III: This City Made Us. I've waited like 16 years for this! No Way Back is an absolute banger. #Music #RockOpera #Rock theprotomen.bandcamp.com/album/act-ii...
October 8, 2025 at 4:54 PM
Second week of new songs for the #Protomen final album Act III: This City Made Us. I've waited like 16 years for this! No Way Back is an absolute banger. #Music #RockOpera #Rock theprotomen.bandcamp.com/album/act-ii...
Hmm. 🤔 Enrollment in bachelor's degrees in #Physics seems to have fallen off a cliff in German universities since the pandemic. Anybody know if this trend has reproduced itself in your country or in another STEM field? #EduSky #AcademicSky #Science 🧪⚛️
Source: www.dpg-physik.de/veroeffentli...
Source: www.dpg-physik.de/veroeffentli...
September 20, 2025 at 8:18 PM
Hmm. 🤔 Enrollment in bachelor's degrees in #Physics seems to have fallen off a cliff in German universities since the pandemic. Anybody know if this trend has reproduced itself in your country or in another STEM field? #EduSky #AcademicSky #Science 🧪⚛️
Source: www.dpg-physik.de/veroeffentli...
Source: www.dpg-physik.de/veroeffentli...
TIL that popcorn is an ancient snack with evidence going back to 4,700 BC in Peru via radiocarbon dating. That's potentially older than the potter's wheel! #Science #Archeology #History 🧪
Source: doi.org/10.1073/pnas...
Source: doi.org/10.1073/pnas...
September 17, 2025 at 5:45 PM
TIL that popcorn is an ancient snack with evidence going back to 4,700 BC in Peru via radiocarbon dating. That's potentially older than the potter's wheel! #Science #Archeology #History 🧪
Source: doi.org/10.1073/pnas...
Source: doi.org/10.1073/pnas...
Oppenheimer-Snyder collapse (Penrose coordinates) shows how #BlackHoles form with radius (x-axis) & time (y). The star's surface (white) becomes the "antihorizon" of the BH (upper half diamond) with a singularity (cyan). #Physics #Astronomy #Science 🧪🔭⚛️
More info: jila.colorado.edu/~ajsh/bh/col...
More info: jila.colorado.edu/~ajsh/bh/col...
September 16, 2025 at 12:24 AM
Oppenheimer-Snyder collapse (Penrose coordinates) shows how #BlackHoles form with radius (x-axis) & time (y). The star's surface (white) becomes the "antihorizon" of the BH (upper half diamond) with a singularity (cyan). #Physics #Astronomy #Science 🧪🔭⚛️
More info: jila.colorado.edu/~ajsh/bh/col...
More info: jila.colorado.edu/~ajsh/bh/col...
#Crocodilian snout bumps = integumentary sensory organs (ISOs). With 4,000 (American alligators) - 9,000 (Nile crocodiles), each is a dome of touch cells that fire at just 0.08 mN or more sensitive than our fingertips! #Science #HerpSky #Biology
See: Leitch & Catania 2012 doi.org/10.1242/jeb....
See: Leitch & Catania 2012 doi.org/10.1242/jeb....
July 21, 2025 at 8:32 PM
#Crocodilian snout bumps = integumentary sensory organs (ISOs). With 4,000 (American alligators) - 9,000 (Nile crocodiles), each is a dome of touch cells that fire at just 0.08 mN or more sensitive than our fingertips! #Science #HerpSky #Biology
See: Leitch & Catania 2012 doi.org/10.1242/jeb....
See: Leitch & Catania 2012 doi.org/10.1242/jeb....
I'm digging the #GitHub style post activity, but for my #BlueSky posts. Thanks @blueskymeter.com! :)
July 20, 2025 at 7:54 PM
I'm digging the #GitHub style post activity, but for my #BlueSky posts. Thanks @blueskymeter.com! :)
The #CMB spectra temperature fluctuations can be broken down using spherical harmonics e.g. monopole + dipole + quadrupole + etc. Like a bumpy potato, the lower order ℓ-multipoles make large-scale bumps; higher order ℓ make tiny bumps. #Science #Physics #Astronomy🧪⚛️🔭
Source: doi.org/10.1086/513698
Source: doi.org/10.1086/513698
July 19, 2025 at 10:34 PM
The #CMB spectra temperature fluctuations can be broken down using spherical harmonics e.g. monopole + dipole + quadrupole + etc. Like a bumpy potato, the lower order ℓ-multipoles make large-scale bumps; higher order ℓ make tiny bumps. #Science #Physics #Astronomy🧪⚛️🔭
Source: doi.org/10.1086/513698
Source: doi.org/10.1086/513698
(1/n) Why do we believe in dark matter when we can't directly see it? The distinction between a "direct" and "indirect" is more a spectrum than a binary. Galaxy rotation is fairly indirect and could be explained by something like modified Newtonian dynamics (MOND). #Science #Physics #Astronomy 🧪⚛️🔭🧵
July 17, 2025 at 1:46 AM
(1/n) Why do we believe in dark matter when we can't directly see it? The distinction between a "direct" and "indirect" is more a spectrum than a binary. Galaxy rotation is fairly indirect and could be explained by something like modified Newtonian dynamics (MOND). #Science #Physics #Astronomy 🧪⚛️🔭🧵
Uranium ore is mostly U-238 - an isotope with a 4.5-billion-year half-life. The fissile star of the show, U-235, makes up just 0.72% of natural uranium. That tiny fraction? It's what fuels reactors and bombs alike. #Science #Physics #NuclearPhysics #Isotopes
Image: en.wikipedia.org/wiki/File:HE...
Image: en.wikipedia.org/wiki/File:HE...
July 7, 2025 at 5:33 PM
Uranium ore is mostly U-238 - an isotope with a 4.5-billion-year half-life. The fissile star of the show, U-235, makes up just 0.72% of natural uranium. That tiny fraction? It's what fuels reactors and bombs alike. #Science #Physics #NuclearPhysics #Isotopes
Image: en.wikipedia.org/wiki/File:HE...
Image: en.wikipedia.org/wiki/File:HE...
The #TopQuark decays too fast to hadronize. Its lifetime (~5×10⁻²⁵ s) is shorter than #QCD timescales (~10⁻²⁴ s). So we see a "bare" quark decay: t → W + b, before confinement. A rare clean look into quark physics. 🧪⚛️ #Science #ParticlePhysics #Physics
Image: commons.m.wikimedia.org/wiki/File:To...
Image: commons.m.wikimedia.org/wiki/File:To...
July 3, 2025 at 1:54 PM
The #TopQuark decays too fast to hadronize. Its lifetime (~5×10⁻²⁵ s) is shorter than #QCD timescales (~10⁻²⁴ s). So we see a "bare" quark decay: t → W + b, before confinement. A rare clean look into quark physics. 🧪⚛️ #Science #ParticlePhysics #Physics
Image: commons.m.wikimedia.org/wiki/File:To...
Image: commons.m.wikimedia.org/wiki/File:To...
#TyrannosaurusRex modeled for the American Museum of Natural History @amnh.org, New York in 1913 and 2020. Notice the original incorrect upright position, tail dragging, and three fingers! We've come a long way in understanding dinosaur anatomy. 🧪🦖 #Dinosaurs #PaleoSky #Fossil #Paleontology #Science
July 2, 2025 at 2:12 PM
#TyrannosaurusRex modeled for the American Museum of Natural History @amnh.org, New York in 1913 and 2020. Notice the original incorrect upright position, tail dragging, and three fingers! We've come a long way in understanding dinosaur anatomy. 🧪🦖 #Dinosaurs #PaleoSky #Fossil #Paleontology #Science
I found this utterly charming #Drawing of acanthodians from the Early Devonian (aka early jawed fishes) which were precursors to modern cartilaginous fish and #Sharks. #Evolution #Biology #Science #PaleoSky 🧪🧬🦈
Image Credit: Stanton F. Fink commons.wikimedia.org/wiki/File:Me...
Image Credit: Stanton F. Fink commons.wikimedia.org/wiki/File:Me...
June 30, 2025 at 11:58 PM
I found this utterly charming #Drawing of acanthodians from the Early Devonian (aka early jawed fishes) which were precursors to modern cartilaginous fish and #Sharks. #Evolution #Biology #Science #PaleoSky 🧪🧬🦈
Image Credit: Stanton F. Fink commons.wikimedia.org/wiki/File:Me...
Image Credit: Stanton F. Fink commons.wikimedia.org/wiki/File:Me...
Congratulations to all 2025 #Graduates of #UArizona College of Tech., Hebei University of Tech! It was an exciting day and a great accomplishment by the students who finished a four-year bilingual (English/Chinese) program in Applied #Physics, #MSE, and #AME #Engineering. #AcademicSky #EduSky
June 14, 2025 at 2:09 PM
Congratulations to all 2025 #Graduates of #UArizona College of Tech., Hebei University of Tech! It was an exciting day and a great accomplishment by the students who finished a four-year bilingual (English/Chinese) program in Applied #Physics, #MSE, and #AME #Engineering. #AcademicSky #EduSky
Side view of a Crookes tube. A high voltage (>5kV) is placed on the cathode(left)/anode(below) in a partial vacuum. The electrons strike the far end which is painted with phosphor making it glow green with cathodoluminescence. The Maltese Cross casts a shadow by blocking rays. #Science #Physics 🧪⚛️
June 13, 2025 at 7:56 AM