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iyz
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Can somebody explain to me what is a manifold.Also what it means for a space to be curved and how we define curvature.I know that a sphere is a curved 2d object, can a curved 3d object live in 3-dimensional space?
iyz said:Can somebody explain to me what is a manifold.Also what it means for a space to be curved and how we define curvature.I know that a sphere is a curved 2d object, can a curved 3d object live in 3-dimensional space?
Manifolds are a bit like pornography: hard to define, but you know one when you see one.
mathwonk said:curvature requires a way to define length. then we compare the radius of circles to their circumference to get curvature. i.e. curvature zero means the circumference is 2π times the radius, and positive curvature means the circumference is less than that and negative curvature means the circumference is more than that. that's all, at least on surfaces.
Unless I'm missing a subtle point here?
A manifold is a mathematical term used to describe a topological space that resembles the properties of Euclidean space near each point. It can also be thought of as a geometric space that can be smoothly mapped onto a Euclidean space.
In 3D space, a manifold is represented as a surface that is curved or bent in a certain way. This curvature is what differentiates it from a flat plane or a straight line. It can also be represented as a set of points that are connected by smooth curves or surfaces.
Curvature in a manifold is significant because it determines the geometric properties of the space. It can affect the shape, length, and angles of curves on the surface. It is also used to classify manifolds into different types, such as positive, negative, or zero curvature.
Curvature in a manifold is measured using mathematical tools called tensors, which can calculate the curvature at each point on the surface. The most commonly used measure of curvature is the Ricci curvature, which is based on the behavior of geodesic curves on the surface.
Manifolds and curvature have various applications in physics, engineering, and computer science. Some examples include the study of space-time in general relativity, the analysis of fluid flow in aerodynamics, and the development of algorithms for machine learning and computer graphics.