Leonardo da Vinci’s sketch of a tree illustrates the principle that combined thickness is preserved at different stages of ramification.

This oak tree has stood in this very spot since long before he or I walked the Earth. It is early winter when MacKenzie, an atmospheric scientist and director of Birmingham University Institute ...

The Windows Spotlight feature provides stunning desktop backgrounds (worth saving!), but the “Learn About This Picture” icon can be an unwelcome distraction. Unfortunately, you can’t just right-click ...