law of diminishing returns. A concept in economics that if one factor of production (number of workers, for example) is increased while other factors (machines and workspace, for example) are held constant, the output per unit of the variable factor will eventually diminish.
History of glass. The history of glassmaking can be traced back to 3500 BCE in Mesopotamia, but Mesopotamians may have created second-rate copies of glass objects from Egypt, where this complex craft actually originated. Other archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or Egypt.
The first plastic cups were invented in the US in the year 1960, it  was patented by the Wilson brand, these cups were made of plastic  and a ribbed tumbler. In the year 199â¦7 the brand Willbrandt  registered a patent for another cup.