new video: "Lagrangian Mechanics: when theoretical physics got real." In addition to some history, I take Newtonian mechanics and derive Hamilton’s principle, revealing how the mysterious quantity K-U naturally appears, answering the common question "why is L=K-U?" youtu.be/QbnkIdw0HJQ 🧪⚛️🔭 #chemsky

Sep. 21, 1909: Einstein presents at the Salzburg conference his discovery that Planck's radiation law hides a quantum Easter egg: the wave-particle duality of light. Details in "This is how the wave-particle duality of light was discovered" youtu.be/f7JvywBOGYY 🧪⚛️🔭 #chemsky

After finding the speed, we attempted to determine the explosive energy of the volcanic eruption. For this we analyzed the decay of the pressure disruption of local pressure as a function of distance, and search for archival data from nuclear explosions and Mt. St. Helens' 1980 eruption [4/n]

After correcting for time zones and calibrating distances from the volcano, we generated this distance vs. arrival time plot. The slope of the beautiful straight line indicates that the Lamb wave moved at a constant speed ~309 m/s, similar to the 319-m/s Lamb wave generated by Krakatoa in 1883 [3/n]

Together with my colleague Sam Rigby from U. Sheffield, we collected 124 pressure measurements from all over the world to track the pressure wave, called Lamb wave. Hunga Tonga–Hunga Ha‘apai island is denoted by the triangle, and the + marker indicates the antipodal point in southern Algeria [2/n]

On Jan 15, 2022, the violent volcanic eruption at Hunga Tonga–Hunga Ha‘apai generated an intense pressure
wave registered by instruments all over the world. That morning I noticed dozens of social-media posts with location and pressure data, which I realized could be used to study the wave 🧪⚛️ [1/n]

In my latest video I showed these "bad derivations" of de Broglie's wavelength that sadly can be found in some #physics and #chemistry textbooks. I share here why these derivations are inconsistent. Friends don't let friends use these "derivations" of de Broglie's wavelength ⚛️🧪🎢 #ITeachPhysics

Today our planet reaches it closest point to the Sun, not very relevant but I use it to emphasize how this is unrelated to the seasons (contrary to the common misconception that the seasons are produced by the Earth-Sun distance) 🧪⚛️

I made a video about book recommendations on quantum mechanics (textbooks, pop-sci, and some in the middle) and by accident discovered that the covers of "The Theoretical Minimum" series by Lenny Susskind form a beautiful continuous collection of physics diagrams youtu.be/3VmPfpkKgM0 🧪⚛️

Today Dec. 21, 2024 at 9:20 UT the northern hemisphere of our planet received the minimal amount of solar radiation, from now on days become longer and the Sun will appear higher in the sky (the exact opposite occurs in the southern hemisphere) 🧪⚛️

Dec. 14, 1900: two months after discovering the formula describing the blackbody radiation Planck used a math trick and found that the hot material and light must exchange energy in discrete amounts: dawn of quantum physics 🧪⚛️ Details in "This math trick revolutionized physics" youtu.be/gXeAp_lyj9s

On November 25, 1915, Einstein presented his masterpiece: "The Field Equations of Gravitation," a new theory of gravitation know today as the Theory of General Relativity. ⚛️🧪Available in English here einsteinpapers.press.princeton.edu/vol6-trans/129

Bingo: fine-structure-constant edition. Find any video about α and identify irrelevant and scientifically meaningless facts about it. I created this for my video about Sommerfeld's atomic model (youtu.be/H4ZnVpiQTDw). During my research I discovered that Sommerfeld's paper has 137 pages! ⚛️🧪

I am preparing a video about Louis de Broglie for my series on quantum mechanics🧪 It is tempting to believe that he just took the wavelength-momentum relation for light and applied it to particles, but the true story is way more interesting than this simple narrative. Still, I had to make this

Paul Ehrenfest lecturing, based on the equations, about how Einstein discovered the wave-particle duality of light in 1909. He was Einstein's great friend but also critic; however, the duality was confirmed by Matrix Mechanics in 1926. Question to Austrian/Dutch physicists: do you draw E backwards?🧪