Picture puzzles that ask you to count objects are surprisingly challenging, even when the image looks simple. The challenge ...

Counting objects is easy whenthe objects have regular motion,but it becomes more difficult when theobjects vibrate or you have to manuallymove them. To deal with this problem,you need a reliable, ...

A red knot is a tiny shorebird that makes an epic 9000-mile journey all the way from the arctic to the tip of southern Chile and back. Biologists and nature enthusiasts congregate at various points ...