Engineering Can you find a surface from a metric?

  • Thread starter Thread starter docnet
  • Start date Start date
  • Tags Tags
    Metric Surface
AI Thread Summary
The discussion centers on the relationship between metrics and surfaces, specifically whether an arbitrary metric can guarantee a corresponding surface embedded in R^3. A metric like ds^2=dr^2+r^2dθ^2+r^2sin^2θdφ^2 indicates a sphere in spherical coordinates. The conversation also explores the possibility of representing metrics using parametric functions, such as x=2√u u and y=v, and whether these can be geometrically demonstrated. Participants question how to define "surface" in the context of different metrics and whether all induced metrics can be represented on paper. The overarching inquiry is about the geometric implications of varying grid spacings in relation to different metrics.
docnet
Messages
796
Reaction score
488
Homework Statement
.
Relevant Equations
.
if a metric like ##ds^2=dr^2+r^2d\theta^2+r^2\sin^2\theta d\phi^2 ## is given, we know it corresponds to a sphere in spherical coordinates .

if you are given an arbitrary metric with two variables for example ##ds^2=\frac{du^2}{u}+dv^2## is ther guarenteed to be a surface embedded in ##R^3## associated with the metric? could a surface be found using python?
 
Physics news on Phys.org
As for your example
w:=2\sqrt{u} u
ds^2=dw^2+dv^2
How are you defining "surface" for ##ds^2=dx^2+dy^2## ?
 
anuttarasammyak said:
How are you defining "surface" for ##ds^2=dx^2+dy^2## ?

ummm I'm not sure if i understand your question.. just a regular plane with the standard basis ##(1,0)## and ##(0,1)##? actually I'm not sure if I understand the question i was trying to ask.

##x=2\sqrt{u}u, y=v## is like a parametric function that corresponds to a map from ##R^2## to ##R^2##, right? like i was wondering if there is a geometrical demonstration for it. like could you scrunch a paper with uniform grid spacing and make another shape with non-standard grid spacing that somehow describes the image geometrically?

like when you wrap a plane around a sphere, you end up deforming the standard grid spacing in a way that reflects the new metric on the sphere.. does every induced metric of this kind have a corresponding surface that can be drawn on a paper?
 
Last edited:
Back
Top