but not in the sense of believing that any merely mechanical contrivance can produce perpetual motion. That there are forces in nature which can and do produce it, is a matter of daily ...

A n international team of researchers described how loops, crucial for the stability of such networks, occur in transport networks found in nature. The researchers observed that when one branch of ...

The shearing of fluids—meaning the sliding of fluid layers over each other under shear forces—is an important concept in nature and in ... forming closed loops without free ends.