Agner Krarup Erlang:
(1 January 1878 – 3 February 1929).
Danish mathematician, statistician and engineer, who invented the fields of traffic engineering and queueing theory.
Erlang’s 1909 paper, and subsequent papers over the decades, are regarded as containing some of most important concepts and techniques for queueing theory.

You don’t really understand simultaneity until you have had your second child.
