Differential geometry of surfaces
In mathematics, the differential geometry of surfaces deals with the differential geometry of smooth surfaces with various additional structures, most often, a Riemannian metric.Surfaces have been extensively studied from various perspectives: extrinsically, relating to their embedding in Euclidean space and intrinsically, reflecting their properties determined solely by the distance within the surface as measured along curves on the surface. One of the fundamental concepts investigated is the Gaussian curvature, first studied in depth by Carl Friedrich Gauss, who showed that curvature was an intrinsic property of a surface, independent of its isometric embedding in Euclidean space. Surfaces naturally arise as graphs of functions of a pair of variables, and sometimes appear in parametric form or as loci associated to space curves. An important role in their study has been played by Lie groups (in the spirit of the Erlangen program), namely the symmetry groups of the Euclidean plane, the sphere and the hyperbolic plane. These Lie groups can be used to describe surfaces of constant Gaussian curvature; they also provide an essential ingredient in the modern approach to intrinsic differential geometry through connections. On the other hand, extrinsic properties relying on an embedding of a surface in Euclidean space have also been extensively studied. This is well illustrated by the non-linear Euler–Lagrange equations in the calculus of variations: although Euler developed the one variable equations to understand geodesics, defined independently of an embedding, one of Lagrange's main applications of the two variable equations was to minimal surfaces, a concept that can only be defined in terms of an embedding. (Wikipedia).
An introduction to surfaces | Differential Geometry 21 | NJ Wildberger
We introduce surfaces, which are the main objects of interest in differential geometry. After a brief introduction, we mention the key notion of orientability, and then discuss the division in the subject between algebraic surfaces and parametrized surfaces. It is very important to have a
From playlist Differential Geometry
Examples of curvatures of surfaces | Differential Geometry 30 | NJ Wildberger
We review the formulas for the curvature of a surface we derived/discussed in the last lecture, and then give explicit examples of how these formulas work out in special cases. The formulas were given in several roughly equivalent forms, applying to different situations. The first applied
From playlist Differential Geometry
Classical curves | Differential Geometry 1 | NJ Wildberger
The first lecture of a beginner's course on Differential Geometry! Given by Prof N J Wildberger of the School of Mathematics and Statistics at UNSW. Differential geometry is the application of calculus and analytic geometry to the study of curves and surfaces, and has numerous applications
From playlist Differential Geometry
Geometric and algebraic aspects of space curves | Differential Geometry 20 | NJ Wildberger
A space curve has associated to it various interesting lines and planes at each point on it. The tangent vector determines a line, normal to that is the normal plane, while the span of adjacent normals (or equivalently the velocity and acceleration) is the osculating plane. In this lectur
From playlist Differential Geometry
The differential calculus for curves (II) | Differential Geometry 8 | NJ Wildberger
In this video we extend Lagrange's approach to the differential calculus to the case of algebraic curves. This means we can study tangent lines, tangent conics and so on to a general curve of the form p(x,y)=0; this includes the situation y=f(x) as a special case. It also allows us to deal
From playlist Differential Geometry
More general surfaces | Differential Geometry 22 | NJ Wildberger
This video follows on from DiffGeom21: An Introduction to surfaces, starting with ruled surfaces. These were studied by Euler, and Monge gave examples of how such surfaces arose from the study of curves, namely as polar developables. A developable surface is a particularly important and us
From playlist Differential Geometry
This video defines a cylindrical surface and explains how to graph a cylindrical surface. http://mathispower4u.yolasite.com/
From playlist Quadric, Surfaces, Cylindrical Coordinates and Spherical Coordinates
Lecture 5: Differential Forms (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
Curvature of a surface, only using calculus
We define the curvature of a surface using an intuitive approach, without using geodesics or tensor calculus.
From playlist Differential geometry
Colloque d'histoire des sciences "Gaston Darboux (1842 - 1917)" - Philippe Nabonnand - 17/11/17
En partenariat avec le séminaire d’histoire des mathématiques de l’IHP Élie Cartan suit le cours de géométrie de Gaston Darboux Philippe Nabonnand, Archives Henri Poincaré, Université de Lorraine) À l’occasion du centenaire de la mort de Gaston Darboux, l’Institut Henri Poincaré souhaite
From playlist Colloque d'histoire des sciences "Gaston Darboux (1842 - 1917)" - 17/11/2017
Lecture 12: Smooth Surfaces I (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
Lecture 14: Discrete Surfaces (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
Lecture 10: Smooth Curves (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
Lecture 1: Overview (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
The Abel Prize announcement 2015 - John Nash & Louis Nirenberg
0:42 The Abel Prize announced by Kirsti Strøm Bull, President of The Norwegian Academy of Science and Letters 2:31 Citation by John Rognes, Chair of the Abel committee 8:50 Popular presentation of the prize winners work by Alex Bellos, British writer, and science communicator 23:09 Phone i
From playlist The Abel Prize announcements
Alex Bellos: PDE's and Geometric analysis explained
Alex Bellos, popular presenter explains the basic concepts behind John Nash and Louis Nirenberg's Abel Prize. This clip is a part of the Abel Prize Announcement 2015. You can view Alex Bellos own YouTube channel here: https://www.youtube.com/user/AlexInNumberland
From playlist Popular presentations
Lecture 13: Smooth Surfaces II (Discrete Differential Geometry)
Full playlist: https://www.youtube.com/playlist?list=PL9_jI1bdZmz0hIrNCMQW1YmZysAiIYSSS For more information see http://geometry.cs.cmu.edu/ddg
From playlist Discrete Differential Geometry - CMU 15-458/858
CS 468: Differential Geometry for Computer Science (camera died 19 minutes in!) Slides: http://graphics.stanford.edu/courses/cs468-13-spring/assets/lecture1.pdf
From playlist Stanford: Differential Geometry for Computer Science (CosmoLearning Computer Science)
Gauss, normals and fundamental forms | Differential Geometry 34 | NJ Wildberger
We introduce the approach of C. F. Gauss to differential geometry, which relies on a parametric description of a surface, and the Gauss - Rodrigues map from an oriented surface S to the unit sphere S^2, which describes how a unit normal moves along the surface. The first fundamental form
From playlist Differential Geometry
In visual computing, point locations are often optimized using a "repulsive" energy, to obtain a nice uniform distribution for tasks ranging from image stippling to mesh generation to fluid simulation. But how do you perform this same kind of repulsive optimization on curves and surfaces?
From playlist Repulsive Videos