Biodegradable polymer which, edible films have gained more attention due to their environmentally-friendly characteristics, vast variety and availability, non-toxicity, and low cost. Biodegradable polymers have a long history, and since many are natural products, the precise timeline of their discovery and use cannot be accurately traced. One of the first medicinal uses of a biodegradable polymer was the catgut suture, which dates back to at least 100 AD. The first catgut sutures were made from the intestines of sheep, but modern catgut sutures are made from purified collagen extracted from the small intestines of cattle, sheep, or goats. The concept of synthetic
Rackets (sport) covered racket court and is now the oldest surviving court in the world, as well as being the oldest indoor sports building in Scotland. It has been restored as a racket hall, but used as an exhibition area. Some private clubs also built courts. Along with real tennis and badminton, rackets was used as an inspiration for the game of lawn tennis, invented in 1873 by Walter Clopton Wingfield. A vacant rackets court built into the University of Chicago's Stagg Field served as the location of the first artificial nuclear chain reaction on December 2, 1942. The Stagg Field court