When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. A massive feature on the moon formed due to lunar rifts, in a surprise revision to earlier ...

This tan paper cut and glued model has thirty-six equal isosceles triangles for sides. Eighteen of these are around the middle, facing in opposite directions as in an antiprism. Nine at each end form ...

This media is in the public domain (free of copyright restrictions). You can copy, modify, and distribute this work without contacting the Smithsonian. For more information, visit the Smithsonian's ...

This is a preview. Log in through your library . Abstract We give an extensive discussion of sphere-preserving maps defined on subdomains of Euclidean n-space, and their relationship to Möbius maps ...