• Welcome to the new Internet Infidels Discussion Board, formerly Talk Freethought.

Tests for Manifolds?

SLD

Contributor
Joined
Feb 25, 2001
Messages
5,134
Location
Birmingham, Alabama
Basic Beliefs
Freethinker
So, just playing around with a graphics program, and using spherical coordinates, phi, rho and r. I graphed this equatio:

D55D5E53-7AE9-4F3F-9E85-0E9DADA989C7.jpeg
here is the result:

60D6B95E-C62E-4433-8316-257898FD21D1.jpeg
Rather odd looking fu cation. The bumpiness is due to the limits of the program, but clearly part of the domain of this function is indeed a smooth manifold. But it doesn’t look like all of it is. Is there a mathematical way to determine whether it is Everywhere?

You can obviously differentiate it with respect to phi and rho. But just visually it doesn’t look like it’s a smooth manifold everywhere.

I’ve created a few other odd ones that I’m not sure about either.
 
Back
Top Bottom