User:Thurth



Seven years ago, I traveled to Iguacu Falls, Brazil. I enjoyed the scenery very much. I think this is the most beautiful place on earth that I have ever been.

Edited articles

 * Gullstrand-Painlevé coordinates
 * Holonomic
 * Monogenic system
 * Nonholonomic system
 * Rheonomous
 * Scleronomous