Self-tying shoes Self-tying shoes Self-tying shoes (also known as "self-lacing" or "power laces") are designed to automatically tighten once the user puts them on. Such shoes were initially depicted in the 1989 science fiction film "Back to the Future II". In April 2009, Nike filed a patent for self-lacing shoes, with a design that bears a resemblance to those worn by Marty in the film "Back to the Future II", raising speculation among fans about a possible debut of self-lacing shoes. In 2014, Tinker Hatfield, the designer of the original Nike shoes as depicted in "Back to the Future II", indicated that
Time travel objects to return to their own past. There are known to be solutions to the equations of general relativity that describe spacetimes which contain closed timelike curves, such as Gödel spacetime, but the physical plausibility of these solutions is uncertain. Many in the scientific community believe that backward time travel is highly unlikely. Any theory that would allow time travel would introduce potential problems of causality. The classic example of a problem involving causality is the "grandfather paradox": what if one were to go back in time and kill one's own grandfather before one's father was conceived? Some physicists, such