Mathematics of rigidity | Nonconvex polyhedra
In geometry, a Bricard octahedron is a member of a family of flexible polyhedra constructed by Raoul Bricard in 1897.The overall shape of one of these polyhedron may change in a continuous motion, without any changes to the lengths of its edges nor to the shapes of its faces.These octahedra were the first flexible polyhedra to be discovered. The Bricard octahedra have six vertices, twelve edges, and eight triangular faces, connected in the same way as a regular octahedron. Unlike the regular octahedron, the Bricard octahedra are all non-convex self-crossing polyhedra. By Cauchy's rigidity theorem, a flexible polyhedron must be non-convex, but there exist other flexible polyhedra without self-crossings. Avoiding self-crossings requires more vertices (at least nine) than the six vertices of the Bricard octahedra. In his publication describing these octahedra, Bricard completely classified the flexible octahedra. His work in this area was later the subject of lectures by Henri Lebesgue at the Collège de France. (Wikipedia).
This shows a 3d print of a mathematical sculpture I produced using shapeways.com. This model is available at http://shpws.me/19O1
From playlist 3D printing
What's an Octagon? Geometry Terms and Definitions
An introduction to the octagon, a fundamental geometric shape. Geometer: Louise McCartney Artwork: Kelly Vivanco Director: Michael Harrison Written & Produced by Kimberly Hatch Harrison and Michael Harrison ♦♦♦♦♦♦♦♦♦♦ Ways to support our channel: ► Join our Patreon : https://www.patre
From playlist Socratica: The Geometry Glossary Series
Octahedron in Geogebra Step by step tutorial here: https://youtu.be/LmCs6dzZreA In case you wanna to pay me a drink: https://www.paypal.me/admirsuljicic/
From playlist Geogebra [Tutoriali]
Everything Matters | Boron | Paul Stepahin | Exploratorium
Join Paul Stepahin for a presentation about quantum mechanics and the elements.Boron is complicated. Elusive. Tough. Created in collisions between cosmic rays and interstellar dust, pure boron may be found in meteoroids, but not naturally on Earth. And yet this relatively uncommon element
From playlist Tales from the Periodic Table
How to construct an Octahedron
How the greeks constructed the 2nd platonic solid: the regular octahedron Source: Euclids Elements Book 13, Proposition 14. In geometry, an octahedron is a polyhedron with eight faces, twelve edges, and six vertices. The term is most commonly used to refer to the regular octahedron, a Plat
From playlist Platonic Solids
Le "Large Hadron Collider" (français)
un apreçu du grand collisionneur de hadrons (LHC) et de son programme de recherche
From playlist Français
Boron Tribromide - Periodic Table of Videos
Debbie, our self-confessed Boron lover, demonstrates the fuming of Boron Tribromide. More links in description below ↓↓↓ Support Periodic Videos on Patreon: https://www.patreon.com/periodicvideos A video on every element: http://bit.ly/118elements More at http://www.periodicvideos.com/
From playlist Molecular Videos - Periodic Videos
Platonic and Archimedean solids
Platonic solids: http://shpws.me/qPNS Archimedean solids: http://shpws.me/qPNV
From playlist 3D printing
What Are Allotropes of Metalloids and Metals | Properties of Matter | Chemistry | FuseSchool
What Are Allotropes of Metalloids and Metals Learn the basics about allotropes of metalloids and metals, as a part of the overall properties of matter topic. An allotrope is basically a different form of the same element, each with distinct physical and chemical properties. For example
From playlist CHEMISTRY
Periodic Table Part 4: Boron Group (B, Al, Ga, In, Tl, Nh)
It's time to check out Group 13 on the periodic table, the boron group. This includes boron, aluminum, gallium, indium, thallium, and nihonium. What can we say about their properties, reactivities, and applications? Let's find out! Watch the whole Inorganic/Organometallic Chemistry playli
From playlist Inorganic/Organometallic Chemistry
Math Mornings at Yale: Asher Auel - Wallpaper, Platonic Solids, and Symmetry
The Platonic solids-the tetrahedron, cube, octahedron, dodecahedron, and icosahedron-are some of the most beautiful and symmetric geometrical objects in 3-dimensional space. Their mysteries started to be unraveled by the ancient Greeks and still fascinate us today. In 1872, the German geom
From playlist Math Mornings at Yale
Journée de la Revue d’histoire des mathématiques - Veronica Gavagna - 01/12/17
Journée de la Revue d’histoire des mathématiques (séance préparée par la rédaction de la RHM) Veronica Gavagna (Università degli Studi di Firenze), « Studies on regular polyhedra in the Renaissance: the case of Francesco Maurolico » ---------------------------------- Vous pouvez nous re
From playlist Séminaire d'Histoire des Mathématiques
See http://thedicelab.com/ for more details. These dice are available at http://www.mathartfun.com/shopsite_sc/store/html/DiceLabDice.html
From playlist Dice
Tetrahedron decomposition (pure CSS 3D)
You can see the live demo here https://codepen.io/thebabydino/pen/OjgWQG/ If the work I've been putting out since early 2012 has helped you in any way or you just like it, please consider supporting it to help me continue and stay afloat. You can do so in one of the following ways: * yo
From playlist CSS variables
Unique way to divide a tetrahedron in half
This is an interesting geometry volume problem using tetrahedrons. We use the volume of a tetrahedron and Cavalieri's principle in 3D.
From playlist Platonic Solids
mandelbrot fractal animation 5
another mandelbrot/julia fractal animation/morph.
From playlist Fractal
Scott Kim - Motley Dissections - G4G13 April 2018
This talk discusses motley dissections — polygons cut into polygons and polyhedra cut into polyhedra such that no two pieces every completely share an edge or a face. The most famous motley dissection is the squared square. My contribution extends this to triangled triangles, pentagoned pe
From playlist G4G13 Videos