George Miller, who wrote the almost-magical essay “The Magical Number Seven, Plus or Minus Two“, died this past week. The essay appeared in the Psychological Review (vol. 101, no. 2, 1956, pp. 343-352). It begins: My problem is that I have been persecuted by an integer. For seven years this number has followed me around, has intruded […]
Tag: number
That man Kaprekar and his damned number
Yutaka Nishiyama writes about a man and his curious number: The number 6174 is a really mysterious number. At first glance, it might not seem so obvious. But as we are about to see, anyone who can subtract can uncover the mystery that makes 6174 so special. In 1949 the mathematician D. R. Kaprekar from […]
The evolution of the billion
David Bradley explains a dramatic, historic passage in the evolution of the meaning of “billion”: …In the issue of Nature dated 2nd July 1992, the journal stated: “…from now on, the English word “billion” will be understood as meaning 10^9 rather than 10^12. It is earnestly hoped that readers will not mistake this upheaval in editorial practice […]