The laces on the left are tied in a strong knot that lies horizontally. The laces on the right are tied in a knot that makes the bow lie vertically and which, according to new research, can come untied more easily.
Asian elephant Shanthi plays in an enclosure at the Elephant Community Center during the unveiling of the major expansion of the elephant house at the Smithsonian's National Zoo in 2013.
Manuel Balce Ceneta/AP
This computer hardware fits into a smart shoe prototype called Sneakairs, unveiled recently by European airline easyJet. The shoes help walkers find their way around through directional vibrations.
Nike-owned Converse, the company responsible for the Chuck Taylor All Star shoe, is suing to stop other shoemakers from copying what it says are distinctive elements of its design.
The slipper is made from thermosetting PVC material. Designer Satsuki Ohata claims that once it hardens to your foot's individual shape, the slippers can be worn inside and outside.