iiinova — where your digital self keeps evolving

Christophe Yamahata @cyamahata.bsky.social · 07/09/2026

Dis-moi, France, qu'est-ce qu'une « bonne droite » ? observablehq.com/@christophe-...

Christophe Yamahata @cyamahata.bsky.social · 08/08/2026

A short video about my Observable notebook for exploring solar eclipses. You can visualize the paths of about 10,000 solar eclipses computed from NASA’s Five Millennium Catalog of Solar Eclipses (−1999 to +3000). 🔗 observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 06/08/2026

❂ On August 12, 2026, the Moon's shadow will sweep across Greenland → Iceland → Portugal → Spain. Visualize the path of nearly 12,000 solar eclipses (−1999 to +3000) in this Observable notebook, computed from NASA's Five Millennium Catalog of Solar Eclipses. observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 30/07/2026

Using Notepad++ to Compile LaTeX observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 28/07/2026

Subtraction through addition: The 9's complement method observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 25/07/2026

Square Root by Hand: The Digit-by-Digit Method youtube.com/shorts/1D9C5... 🔗https://observablehq.com/@christophe-yamahata/square-root-by-hand-digit-by-digit-method?collection=@christophe-yamahata/mathematics

youtube.com

Square Root by Hand (Digit-by-Digit Method) #maths #education

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 19/07/2026

Calculate square root by hand using the digit-by-digit method:: 1) Group digits in pairs starting from the decimal point, 2) Find each digit of the root one by one using the algebraic identity (20X + Y) × Y ≤ Remainder. observablehq.com/@christophe-...

Square root by hand: Digit-by-digit method

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Christophe Yamahata @cyamahata.bsky.social · 06/06/2026

This mechanism was invented by Albert Pellaton to rewind the mainspring in mechanical watches. grabcad.com/library/pell...

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Christophe Yamahata @cyamahata.bsky.social · 12/04/2026

By combining Tycho Brahe's precise planetary observations with osculating orbital elements, we can reconstruct the orbits of Mercury and the other planets as they appeared at the end of the 16th century. Explore the complete process in this @observablehq notebook. observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 21/03/2026

Brother Printer: The No Paper Error What this tiny POM plastic component designed for 𝘱𝘭𝘢𝘯𝘯𝘦𝘥 𝘰𝘣𝘴𝘰𝘭𝘦𝘴𝘤𝘦𝘯𝘤𝘦? #obsolescence #DIY #repair youtube.com/shorts/5i75p...

youtube.com

Brother Printer: The No Paper Error #obsolescence #DIY #repair

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 01/03/2026

Richard Feynman was invited to give the 1964 Messenger Lectures at Cornell University. He ended up with 7 lectures — The Character of Physical Law. Find them in this playlist: www.youtube.com/watch?v=kqS2...

youtube.com

Richard Feynman — On the Incompleteness of Physical Laws

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 27/02/2026

Seeking New Laws (Colorized) 7th lecture delivered by Richard Feynman in 1964 at Cornell University. Restored edition colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺. Audio enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity. Transcript: ww.feynmanlectures.caltech.edu/fml.html youtu.be/SHgGW-ChQw8?...

youtu.be

⑦ Richard Feynman: Seeking New Laws (Colorized) — The Character of Physical Law

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 22/02/2026

Symmetry in Physical Law (Colorized) 4th lecture delivered by Richard Feynman in 1964 at Cornell University. Restored edition colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺. Audio enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity. Transcript: www.feynmanlectures.caltech.edu/fml.html youtu.be/3JbB7XvBWgQ?...

youtu.be

Richard Feynman: Symmetry in Physical Law (Colorized) — The Character of Physical Law

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 22/02/2026

The Relation of Mathematics and Physics Lecture delivered by Richard Feynman in 1964 at Cornell University. Restored edition colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺. Audio enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity. Transcript: www.feynmanlectures.caltech.edu/fml.html youtu.be/XeD8zT596mk?...

youtu.be

Richard Feynman: The Relation of Mathematics and Physics (Colorized) — The Character of Physical Law

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 17/02/2026

The Distinction of Past and Future Lecture delivered by Richard Feynman in 1964 at Cornell University. Restored edition colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺. Audio enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity. youtube.com/watch?v=kYXl...

youtube.com

Richard Feynman: The Distinction of Past and Future (Colorized) — The Character of Physical Law

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 10/02/2026

The Great Conservation Principles 3rd lecture delivered by Richard Feynman in 1964 at Cornell University. Restored edition colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺. Audio enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity. youtu.be/hOCA43RtERU?...

youtu.be

Richard Feynman: The Character of Physical Law — The Great Conservation Principles (Colorized)

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 08/02/2026

Lecture delivered by Richard P. Feynman in 1964 at Cornell University. This restored edition has been colorized using 𝘋𝘦𝘖𝘭𝘥𝘪𝘧𝘺, and the audio has been enhanced with Adobe AI 𝘌𝘯𝘩𝘢𝘯𝘤𝘦 𝘚𝘱𝘦𝘦𝘤𝘩 v2 to improve clarity while preserving the authenticity of the original lecture. youtu.be/dDKYHLDp8YQ

youtu.be

Richard Feynman: The Character of Physical Law — The Law of Gravitation (Colorized)

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 18/01/2026

Stop Overpaying: Professional Free Tools for Engineers Check out this playlist to discover awesome free CAD, FEM & engineering tools: www.youtube.com/playlist?lis...

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Christophe Yamahata @cyamahata.bsky.social · 11/01/2026

You don't need expensive commercial software to run high-end FEM. Master open-source mechanical FEM using Elmer 9.0, FreeCAD 1.0, and ParaView 6.0. Full workflow tutorial: youtu.be/8RLimNWzdyo?... #ElmerFEM #FreeCAD #ParaView

youtu.be

Tutorial: Mechanical FEM Simulation Using Elmer, FreeCAD, and ParaView

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 21/12/2025

🪰 𝗦𝘄𝗮𝘁𝗺𝗮𝗻 𝗙𝗹𝗲𝘅𝘂𝗿𝗲 – This monolithic design features a rotary flexure joint that creates a smooth virtual pivot, allowing this “swatman” to shake his head with pure compliance. Check out this animated model in #3D, #VR or #AR skfb.ly/pENzD via @sketchfab.bsky.social

skfb.ly

Swatman Flexure - 3D model by C. Yamahata (@cyamahat)

This monolithic design features a rotary flexure joint that creates a smooth virtual pivot, allowing this “swatman” to shake his head with pure compliance. - Swatman Flexure - 3D model by ...

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Christophe Yamahata @cyamahata.bsky.social · 23/11/2025

⚡️Electrothermal microactuator simulation completed in Elmer 9 Joule heating → thermal expansion → few µm tip displacement Temperature distribution + beam deformation beautifully rendered in ParaView 6 🌡️📈 #Multiphysics #ElmerFEM #ParaView #MEMS youtu.be/qBL2DHKBraU?...

youtu.be

FEM Simulation of an Electrothermal Microactuator using Elmer

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 16/11/2025

Multiphysics finite element simulation of a MEMS electrothermal actuator, performed using Elmer FEM Solver (v9, 2025) and visualized in ParaView 6. #ElmerFEM #MEMS #FiniteElement #Simulation

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Christophe Yamahata @cyamahata.bsky.social · 16/11/2025

U-shaped electrothermal MEMS actuator from Elmer's non-GUI tutorial! Multiphysics FEM simulation completed with Elmer FEM, animated in Blender with shape keys. FreeCAD (@freecad.org) also implied in the process. Details are in the model description on Sketchfab. skfb.ly/pDyS8

skfb.ly

MEMS Electrothermal Actuator - 3D model by C. Yamahata (@cyamahat)

Working Principle This asymmetric U-shaped thermal actuator consists of a narrow “hot” arm and a wider “cold” arm connected in series to an electrical circuit. When current flo...

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Christophe Yamahata @cyamahata.bsky.social · 08/11/2025

I have prepared a Google Colab notebook with an updated, streamlined version of the original DeOldify video colorization notebook. Here’s a short demo made from black-and-white films. youtu.be/_NMNLvlSy9g?...

youtu.be

DeOldify: Colorized black-and-white movies

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 26/10/2025

In the closing years of the 19th century, the world was entering the Electric Revolution. Although Edison didn’t win the "War of the Currents," his work on the electric light bulb led to an unexpected discovery — one that would ultimately pave the way for the electronics of the future.

youtu.be

A Short History of the Transistor

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 04/10/2025

The Stockett Continuous-Motion Breech-Loading Mechanism is an elegant example of mechanical ingenuity. With a single turn of the crank, it completes the full sequence of breech rotation, translation, and pivot. This YouTube video shows how the breech block moves smoothly through coordinated motion.

youtu.be

Stockett Continuous-Motion Breech-Loading Mechanism for Heavy Guns

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 17/08/2025

Copernicus animated with grokimagine.ai

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Christophe Yamahata @cyamahata.bsky.social · 16/08/2025

I'm back to silicon microelectromechanical systems (MEMS) in Neuchâtel, Switzerland.

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Christophe Yamahata @cyamahata.bsky.social · 04/08/2025

You are interested in quantum mechanics and come across a lecture given by Richard Feynman in 1964. Unfortunately, the audio recording is of poor quality, which is common for that period. So you decide to use artificial intelligence #AI #adobepodcast #physics youtube.com/shorts/qneJ_...

youtube.com

AI-enhanced Audio: Feynman Lecture on Quantum Mechanics #AI #adobepodcast #voicecloning #physics

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 02/08/2025

Richard Feynman was a legendary lecturer. His captivating aura shines in this audio-remastered video on the double-slit experiment: youtu.be/vbn8eMRZUS4 #Feynman #QuantumPhysics

youtu.be

Richard Feynman: Probability & Uncertainty - The Quantum Mechanical View of Nature |Remastered Audio

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 30/06/2025

🎞️ Just released a new video! A DIY experiment using a holographic diffraction grating film to observe 𝗙𝗿𝗮𝘂𝗻𝗵𝗼𝗳𝗲𝗿 𝗹𝗶𝗻𝗲𝘀 — the dark absorption lines in the solar spectrum. Also includes spectrometer measurements, fluorescence with olive oil + blue LED, and a teardown of the Ocean Optics USB2000.

youtu.be

Spectrometer, DIY Experiment & Laboratory Spectrometer | Observing Fraunhofer Lines and Fluorescence

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 20/06/2025

🌞 It's the summer solstice in the Northern Hemisphere — the perfect time to try a DIY physics experiment: Observing the Fraunhofer absorption lines of the Sun. With the naked eye, you can clearly observe dark lines — these are the Fraunhofer absorption lines in the solar spectrum.

$DIY: Observing the Fraunhofer absorption lines of the Sun To carry out this experiment, you’ll simply need: – Sunshine (clear skies), – A diffraction grating (e.g., Edmund Optics #54-510), – A radio antenna (a thin reflective surface works), – A tube (such as a vacuum cleaner hose). You'll find the setup in the illustration. With the naked eye, you can clearly observe dark lines — these are the Fraunhofer absorption lines in the solar spectrum. If your curiosity takes you further, check out the Wikipedia page and the solar spectrum curve I recorded using a calibrated optical spectrometer: 🔗 https://en.wikipedia.org/wiki/File:Solar_spectral_irradiance.svg$

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Christophe Yamahata @cyamahata.bsky.social · 06/06/2025

Mars orbits the Sun in 687 days, nearly twice Earth's 365-day orbital period. Mars' apparent retrograde motion occurs approximately every two years, when Earth catches and passes Mars. 🔗 observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 05/06/2025

The Sketchfab Viewer API enables dynamic manipulation of embedded 3D models in web applications using <iframe>. It provides control over model properties, such as orientation, camera settings, and lighting. 🔗 observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 02/06/2025

🧛 Night falls. 🕚 Fangs out! Watch the Konstantin Chaykin Dracula timepiece extend its fangs at midnight. Visualization realized with JavaScript via animation of an SVG file. 🔗 observablehq.com/@christophe-... #javascript #svg #observable #horology

The Dracula watch extends its fangs at midnight.

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Christophe Yamahata @cyamahata.bsky.social · 29/05/2025

I’ve used three-gpu-pathtracer by @gkjohnson.bsky.social to create an online demonstration featuring optical prisms. The result is mindblowing, accurately capturing the multiple reflections and refractions of real-world optical elements. 🔗 Explore it on GitHub: cyamahat.github.io/three-gpu-pa...

Dove prism. A Dove prism rotates an image by twice its rotation about the longitudinal axis.

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Christophe Yamahata @cyamahata.bsky.social · 20/05/2025

Rotation of the Dove prism by angle θ causes image rotation of 2θ. Learn more about the Dove prism and panoramic telescope in this video: youtu.be/fu5VCT6Hh1A #optics #prism #keyshot #PBR

Dove prism, image rotation, and PBR rendering in KeyShot 9.

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Christophe Yamahata @cyamahata.bsky.social · 18/05/2025

The Dove prism is an optical device that rotates an image by twice its rotation about the longitudinal axis, making it ideal for image rotation instruments. This prism is key to the panoramic telescope, an optical instrument used in field artillery. #keyshot #sketchfab #howitzer #optics #pbr

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Christophe Yamahata @cyamahata.bsky.social · 16/05/2025

I own a 𝐑𝐮𝐧𝐝𝐛𝐥𝐢𝐜𝐤𝐟𝐞𝐫𝐧𝐫𝐨𝐡𝐫. Vasistas? It's a 𝗽𝗮𝗻𝗼𝗿𝗮𝗺𝗶𝗰 𝘁𝗲𝗹𝗲𝘀𝗰𝗼𝗽𝗲, in English terms. At its core is a Dove prism, an optical element with the remarkable ability to rotate images at twice the rate of its own rotation around the longitudinal axis, making it ideal for image rotation applications.

youtu.be

Panoramic telescope | Rundblickfernrohr

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 06/05/2025

Here is a 1 minute teaser for my tutorial on animating flexure mechanisms with FreeCAD & Blender. The system showcased in this video is the compliant mechanism from Patek Philippe’s Aquanaut Travel Time. 📐 Animated model of "the crab" on Sketchfab: skfb.ly/pwHIW youtu.be/OWDF3tjw4NI?...

youtu.be

🦀 "The Crab": Flexure Mechanism Animated using FreeCAD & Blender! #PatekPhilippe #FreeCAD #Blender

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 05/05/2025

Patek Philippe Aquanaut 5650G: GMT Time Zone Adjustment See the 3D animated model of the compliant mechanism on Sketchfab: skfb.ly/pwHIW

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Christophe Yamahata @cyamahata.bsky.social · 03/05/2025

This illustration highlights the key step for animating flexible structures using FreeCAD and Blender. Check out the full tutorial video: youtu.be/n5fE4dAepH0 Illustration: "The Crab" (Patek Philippe compliant mechanism) skfb.ly/pwCRq #3DAnimation #FreeCAD #Blender #Sketchfab

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Christophe Yamahata @cyamahata.bsky.social · 03/05/2025

The "Crab" is a compliant mechanism used to adjust GMT time. It is featured in Patek Philippe Advanced Research’s Aquanaut Travel Time. Model recreated based on the manufacturer’s marketing materials. To animate the model, I used FreeCAD’s FEM workbench and Blender. sketchfab.com/3d-models/th...

sketchfab.com

The "Crab" (Compliant mechanism, Patek Philippe) - 3D model by C. Yamahata (@cyamahat)

Compliant mechanisms replace traditional articulations with flexible structures, eliminating the need for lubrication and significantly reducing wear. Patek Philippe realised this monolithic complian...

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Christophe Yamahata @cyamahata.bsky.social · 30/04/2025

Just published a LinkedIn article to complement my recent YouTube tutorial: Simulating & Animating a Compression Spring with FreeCAD 1.0 + Blender 3.6 🔗 www.linkedin.com/pulse/simula... #FreeCAD #Blender #Sketchfab

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Christophe Yamahata @cyamahata.bsky.social · 30/04/2025

Just published a tutorial on how to simulate and animate a compression spring using FreeCAD 1.0 and Blender 3.6 — two powerful, open-source softwares. 🎥 Watch the full tutorial: youtu.be/n5fE4dAepH0?... 📦 You can download the STEP file on Sketchfab: skfb.ly/pwCRq #FreeCAD #Blender3D

youtu.be

Tutorial: Simulate and Animate of a Compression Spring Using FreeCAD 1.0 and Blender 3.6

YouTube video by Christophe Yamahata

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Christophe Yamahata @cyamahata.bsky.social · 03/04/2025

Caution, folks: From now on, Idiocracy teaches you math. The McDonald's formula applies everywhere beyond the Gulf of America, President Donald Camacho says. ------ Message from @KushDesai47 (White House Deputy Press Secretary) x.com/KushDesai47/...

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Christophe Yamahata @cyamahata.bsky.social · 19/03/2025

The Frankford Arsenal Prism No. 7 is an optical device designed to maintain the correct orientation of an image, ensuring it is neither inverted nor reverted. Featuring a roof-like structure, this prism operates on principles similar to those of the Amici prism. observablehq.com/@christophe-...

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Christophe Yamahata @cyamahata.bsky.social · 05/03/2025

Get a taste of Machine Learning with this CodePen demo on Time Series Forecasting using TensorFlow.js 📈🤖 LSTM captures trends and seasonal patterns. Plateaued validation loss and a small train-validation gap suggest the model generalizes well despite mild overfitting. codepen.io/Christophe-Y...

In this example, the Long Short-Term Memory (LSTM) model effectively captures both long-term trends
and seasonal patterns. The train and validation losses converge, indicating strong learning with mild
overfitting. Since the validation loss has plateaued and the train-validation gap remains small,
generalization is not significantly impacted. Early stopping could have been applied sooner to reduce
unnecessary training.

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