Dodecahedral molecular geometry

How to Construct a Dodecahedron

How the greeks constructed the Dodecahedron. Euclids Elements Book 13, Proposition 17. In geometry, a dodecahedron is any polyhedron with twelve flat faces. The most familiar dodecahedron is the regular dodecahedron with regular pentagons as faces, which is a Platonic solid. A regular dode

From playlist Platonic Solids

Canonical structures inside the Platonic solids III | Universal Hyperbolic Geometry 51

The dodecahedron is surely one of the truly great mathematical objects---revered by the ancient Greeks, Kepler, and many mathematicians since. Its symmetries are particularly rich, and in this video we look at how to see the five-fold and six-fold symmetries of this object via internal str

From playlist Universal Hyperbolic Geometry

The remarkable Platonic solids II: symmetry | Universal Hyperbolic Geometry 48 | NJ Wildberger

We look at the symmetries of the Platonic solids, starting here with rigid motions, which are essentially rotations about fixed axes. We use the normalization of angle whereby one full turn has the value one, and also connect the number of rigid motions with the number of directed edges.

From playlist Universal Hyperbolic Geometry

Inside-Out Logic

A fold-up, slice-and-dice dodecahedron and its complement. With a 3D printer, you can make your own using the files here: http://georgehart.com/rp/T-O-M/t-o-m.html

From playlist Odds and Ends

Day 14 ceramic crystal structures

0:00 reading quiz 5:25 HCP structure and close-packing 10:27 theoretical density calculation 15:00 difference between observed and theoretical densities 18:16 ceramic crystal structures and using rc/ra ratio to determine coordination 23:26 rock salt (NaCl) structure 29:28 cesium chloride (

From playlist Introduction to Materials Science and Engineering Fall 2017

The Pop-up Dodecahedron

Instruction to download http://singingbanana.com/popupdodecahedron.pdf More information about the dodecahedron that I would have like to have gone into in this video http://uk.youtube.com/watch?v=-lqpSpje42o Dodecahedron at wikipedia http://en.wikipedia.org/wiki/Dodecahedron Plato

From playlist My Maths Videos

Mathematics as Metaphor - Curtis McMullen (Harvard University)

Public lecture

From playlist Mathematics Research Center

ceramic crystal structures

0:00 coordination of hexagonal close-packed HCP structure 4:40 theoretical density 21:37 structure of ceramics using cation/anion ratio 30:65 NaCl rock salt structure 33:05 CsCl structure 35:18 ZnS zinc blende structure 39:00 solving for lattice parameter in terms of cation and anion radii

From playlist Introduction to Materials Science & Engineering Fall 2019

Using a set of points determine if the figure is a parallelogram using the midpoint formula

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane

How do ceramic crystal structures differ from metal crystal structures?

Metal crystal structures are much simpler than ceramic structures. This is due to two reasons. First, ceramics have positive and negative charged ions. Cations and ions must maintain charge neutrality. Second, the size of cations and anions are very different! Structures with multiple diff

From playlist Materials Sciences 101 - Introduction to Materials Science & Engineering 2020

Dodecahedral holonomy maze

Available from Shapeways: https://www.shapeways.com/shops/henryseg?section=Holonomy+mazes Thanks to Sabetta Matsumoto and Chaim Goodman-Strauss for building the sculpture, to Saul Schleimer for naming the "rook", and to all of them for helpful conversations.

From playlist 3D printing

"Illustrating Geometry" exhibition at SCGP, Artist's talk: "Sculpture in four-dimensions"

Slides: http://www.math.okstate.edu/~segerman/talks/sculpture_in_4-dimensions.pdf This video is also available at the Simons Center website, at http://scgp.stonybrook.edu/archives/11540 Thanks to Josh Klein for filming and editing.

From playlist 3D printing

Determine if a set of points makes up a rectangle using the distance formula

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane

12 magnets show how viruses are built

The first 200 people to sign up at https://brilliant.org/stevemould/ will get 20% off an annual subscription that gives you access to the full archive of Daily Challenges and every single course. The way viruses self assemble from proteins that a jumbling around in an infected cell is rea

From playlist Chemistry

Determining if a set of points makes a parallelogram or not

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane

Rhombofoam in Zome – Scott Vorthmann

Rhombofoam is a pattern that fills 3D space in all the ways that a golden rhombohedron does, while forming dodecahedral and 16-sided cells that have the topology of foam: three cells around each edge, and four around each vertex. The result is a foam model that has the symmetries of a quas

From playlist G4G12 Videos

Combinatorics and Geometry to Arithmetic of Circle Packings - Nakamura

Speaker: Kei Nakamura (Rutgers) Title: Combinatorics and Geometry to Arithmetic of Circle Packings Abstract: The Koebe-Andreev-Thurston/Schramm theorem assigns a conformally rigid fi-nite circle packing to a convex polyhedron, and then successive inversions yield a conformally rigid infin

From playlist Mathematics

Determine if a set of points is a parallelogram using the distance formula

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane

Coordination Compounds: Geometry and Nomenclature

We have been learning a lot about a wide variety of compounds, but we haven't really looked much at the transition metals. These also form compounds called coordination compounds, and the types of bonds involved in these compounds is quite a bit different from what we are used to, as are t

From playlist General Chemistry

Determine if a set of points is a parallelogram by using the slope formula

👉 Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr

From playlist Quadrilaterals on a Coordinate Plane