A dodecahedral number is a figurate number that represents a dodecahedron. The nth dodecahedral number is given by the formula The first such numbers are 0, 1, 20, 84, 220, 455, 816, 1330, 2024, 2925, 4060, 5456, 7140, 9139, 11480, … (sequence in the OEIS). (Wikipedia).
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
Post-it Note Dodecahedron: Your Photos
From playlist My Maths Videos
In this veideo we continue our look in to the dihedral groups, specifically, the dihedral group with six elements. We note that two of the permutation in the group are special in that they commute with all the other elements in the group. In the next video I'll show you that these two el
From playlist Abstract algebra
Abstract Algebra - 1.3 The Dihedral Groups
Building on what we now know about the symmetries of a square, we generalize to what we can determine about any of the dihedral groups for n=3 or greater for regular n-gons (equilateral triangle, square, regular pentagon, etc.) Video Chapters: Intro 0:00 Recap of Cayley Tables 0:08 D3, D4
From playlist Abstract Algebra - Entire Course
Visualizing decimal numbers and their arithmetic 67 | Arithmetic and Geometry Math Foundations
This video gives a precise definition of a decimal number as a special kind of rational number; one for which there is an expression a/b where a and b are integers, with b a power of ten. For such a number we can extend the Hindu-Arabic notation for integers by introducing the decimal form
From playlist Math Foundations
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
To Build Viruses: A Markov Chain Monte Carlo Algorithm for Stimulating Viral Assembly Kinetics
For the latest information, please visit: http://www.wolfram.com Speaker: Nicholas Brunk Wolfram developers and colleagues discussed the latest in innovative technologies for cloud computing, interactive deployment, mobile devices, and more.
From playlist Wolfram Technology Conference 2015
Bridges 2014 talk: The quaternion group as a symmetry group
This is a talk I gave at the Bridges conference on mathematics and the arts (http://bridgesmathart.org/), on 18th August 2014, about my paper with Vi Hart with the same title. The slides are available at https://www.math.okstate.edu/~segerman/talks/quaternion_group_as_a_symmetry_group.pdf
From playlist 3D printing
Mathematics as Metaphor - Curtis McMullen (Harvard University)
Public lecture
From playlist Mathematics Research Center
Ex 1: Apply Divisibility Rules to a 4 Digit Number
This video explains how to apply the divisibility rules for 2, 3, 4, 5, 6, 8, 9, and 10. http://mathispower4u.com
From playlist Factors, Prime Factors, and Least Common Factors
This shows a 3d print of a puzzle I produced using shapeways.com. This is joint work with Saul Schleimer. This is available at http://shpws.me/lmxi. A larger version of the puzzle is available at http://shpws.me/lmxi.
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
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
This video covers the divisibility rules for 2,3,4,5,6,8,9,and 10. http://mathispower4u.yolasite.com/
From playlist Factors, Prime Factors, and Least Common Factors
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
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
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
Area of dodecagon from a square!
This is a short, animated visual proof demonstrating that the area of a regular dodecagon inscribed in the unit circle has an area of exactly 3. #math #manim #visualproof #mathvideo #geometry #mathshorts #geometry #mtbos #animation #theorem #pww #proofwithoutwords #proof #it
From playlist MathShorts
How to build a nanocage: Self-assembling silica
Researchers have created and imaged a self-assembling silica dodecahedron. The nanocage, measuring only 11.8nm across, could one day be used in cancer therapies. Find out more in this Nature Video. Read more in the research paper: https://www.nature.com/articles/s41586-018-0221-0 20th Ju
From playlist Technology