Rotational symmetry | Finite groups
In mathematics, and especially in geometry, an object has icosahedral symmetry if it has the same symmetries as a regular icosahedron. Examples of other polyhedra with icosahedral symmetry include the regular dodecahedron (the dual of the icosahedron) and the rhombic triacontahedron. Every polyhedron with icosahedral symmetry has 60 rotational (or orientation-preserving) symmetries and 60 orientation-reversing symmetries (that combine a rotation and a reflection), for a total symmetry order of 120. The full symmetry group is the Coxeter group of type H3. It may be represented by Coxeter notation [5,3] and Coxeter diagram . The set of rotational symmetries forms a subgroup that is isomorphic to the alternating group A5 on 5 letters. (Wikipedia).
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
How to Construct an Icosahedron
How the greeks constructed the icosahedron. Source: Euclids Elements Book 13, Proposition 16. In geometry, a regular icosahedron is a convex polyhedron with 20 faces, 30 edges and 12 vertices. It is one of the five Platonic solids, and the one with the most faces. https://www.etsy.com/lis
From playlist Platonic Solids
Group theory 27: The icosahedral group
This lecture is part of an online math course on group theory. The lecture is about a few examples of groups, in particular the icosahedral group. In it we see that the icosahedral group is the only simple group of order 60, and show that all larger alternating groups are simple.
From playlist Group theory
This shows a 3d print of a mathematical sculpture I produced using shapeways.com. This model is available at http://shpws.me/q0PF.
From playlist 3D printing
Group theory 28: Groups of order 120, 168
This lecture is part of an online math course on group theory. It discusses some examples of groups of order 120 or 168: the binary icosahedral group, the symmetric group, and the symmetries of the Fano plane.
From playlist Group theory
Seminar: Five-fold symmetry, Schiffler points and the twisted icosahedron
This is a seminar talk given at UNSW in the School of Mathematics and Statistics. It discusses joint work with Dr. Nguyen Le of San Francisco State University on a combination of projective geometry and triangle geometry, figuring five fold symmetry, dihedral orderings, a lovely distance r
From playlist MathSeminars
The physics of virus self-assembly by Vinothan N. Manoharan
COLLOQUIUM : THE PHYSICS OF VIRUS SELF-ASSEMBLY SPEAKER : Vinothan N. Manoharan (Harvard University, US) DATE : 05 April 2021 VENUE : Online Colloquium ABSTRACT Simple viruses consist of RNA and proteins that form a shell (called a capsid) that protects the RNA. The capsid is highly
From playlist ICTS Colloquia
Competitive nucleation in nanoparticle clusters by Richard Bowles
Conference and School on Nucleation Aggregation and Growth URL: https://www.icts.res.in/program/NAG2010 DATES: Monday 26 July, 2010 - Friday 06 Aug, 2010 VENUE : Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru DESCRIPTION: Venue: Jawaharlal Nehru Centre for Advance
From playlist Conference and School on Nucleation Aggregation and Growth
Eleftherios Pavlides - Elastegrity Geometry of Motion - G4G13 Apr 2018
"The Chiral Icosahedral Hinge Elastegrity resulted from a Bauhaus paper folding exercise, that asks material and structure to dictate form. The key new object obtained in 1982 involved cutting slits into folded pieces of paper and weaving them into 8 irregular isosceles tetrahedra, attache
From playlist G4G13 Videos
Mod-01 Lec-12 Surface Effects and Physical properties of nanomaterials
Nanostructures and Nanomaterials: Characterization and Properties by Characterization and Properties by Dr. Kantesh Balani & Dr. Anandh Subramaniam,Department of Nanotechnology,IIT Kanpur.For more details on NPTEL visit http://nptel.ac.in.
From playlist IIT Kanpur: Nanostructures and Nanomaterials | CosmoLearning.org
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
What are the names of different types of polygons based on the number of sides
👉 Learn about polygons and how to classify them. A polygon is a plane shape bounded by a finite chain of straight lines. A polygon can be concave or convex and it can also be regular or irregular. A concave polygon is a polygon in which at least one of its interior angles is greater than 1
From playlist Classify Polygons
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
👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl
From playlist Types of Triangles and Their Properties
Gauge Equivariant Convolutional Networks and the Icosahedral CNN
Ever wanted to do a convolution on a Klein Bottle? This paper defines CNNs over manifolds such that they are independent of which coordinate frame you choose. Amazingly, this then results in an efficient practical method to achieve state-of-the-art in several tasks! https://arxiv.org/abs/
From playlist Deep Learning Architectures
👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl
From playlist Types of Triangles and Their Properties
What is an equilateral triangle
👉 Learn the essential definitions of triangles. A triangle is a polygon with three sides. Triangles are classified on the basis of their angles or on the basis of their side lengths. The classification of triangles on the bases of their angles are: acute, right and obtuse triangles. The cl
From playlist Types of Triangles and Their Properties
This is an informal talk on sporadic groups given to the Archimedeans (the Cambridge undergraduate mathematical society). It discusses the classification of finite simple groups and some of the sporadic groups, and finishes by briefly describing monstrous moonshine. For other Archimedeans
From playlist Math talks