Differential Geometry

Area of Parametrized Surfaces and Wormholes

for Professor Sormani's Inspiring Talks series

Dr. Jorge Basilio (gbasilio@ucla.edu)

Updated: May 1, 2020

Playlist

Lecture Notes

Surfaces of Revolution

Click the “Activate” button below to run an application that investigages wormholes as surfaces of revolution.

Example: Wormhole 1

We investigate the surface of revolution determined by the curve: \( C: \begin{cases} x = t \\ y = \cosh(t) \end{cases} \) for \( t \in (-1,1) \)

Example: Wormhole 2

We investigate the surface of revolution determined by the curve: \( C: \begin{cases} x = t \\ y = (1/2)t^2 + 1 \end{cases} \) for \( t \in (-1,1) \)

Example: Wormhole 3

We investigate the surface of revolution determined by the curve: \( C: \begin{cases} x = t \\ y = 2+\cos(t) \end{cases} \) for \( t \in (0,2\pi) \)

Arclength

Click the “Evaluate Sage Code” button below to run an application that numerical approximation to arclength.

Notice that computing the arclength of \(f(t)=2+\cos(t)\) leads to a difficult integral that SAGE can't compute a closed form answer. This is a so-called elliptic integral and there is no "elementary function" that gives us this value.

We need to compute the integral numerically as above.

If you want to see SAGE struggle and try to give the exact answer, run the code below (warning: might take a loooong time to evaluate).

Your own SAGE calculations