The statement that the number of transistors that can be placed on an integrated circuit doubles every two years. This statement was first made by Gordon Moore (1929– ), the president of Intel, in 1965 and it has remained valid for the first fifty years of the existence of integrated circuits. However, there are various reasons for thinking that this will come to an end in the future. For example, as circuits become smaller, the quantum effects associated with individual atoms and electrons become more significant.