Mathematical Science Writers without PhD Is there science writers who have written on mathematics without holding a ph.d in the subject? I am aware that Robert Kanigle is one such but does there exist any other?

Nate Silver who wrote "The Signal and the Noise" holds a BA in Economics,

The book describes methods of mathematical model-building using
  probability and statistics. Silver takes a big-picture approach to
  using statistical tools, combining sources of unique data (e.g.,
  timing a minor league ball player's fastball using a radar gun), with
  historical data and principles of sound statistical analysis;
  https://en.wikipedia.org/wiki/Nate_Silver

Peter L. Bernestein who wrote "Against The Gods: The Remarkable Story of Risk" also graduated in Economics,

In 1998, it was awarded the Clarence Arthur Kulp/Elizur Wright
  Memorial Book Award from The American Risk and Insurance Association
  (ARIA) as an outstanding original contribution to the literature of
  risk and insurance.
  https://en.wikipedia.org/wiki/Peter_L._Bernstein

