"One of my favourite examples of early interactions between mathematics and medicine (although perhaps this is stretching things just a little) is Robert Recorde, a physician at the court of King Edward VI of England, but also a mathematical teacher of note and the rst to use the modern "=" sign. In 1557 he published The Whetstone of Witte, in which he writes

...and to avoide the tediouse repetition of these woordes : is equalle to : I will sette as I doe often in woorke... , a paire of paralleles, or Gemowe lines of one lengthe, thus: ===========, bicause noe. 2. thynges, can be moare equalle."

То есть, знак равенства произошёл из астрологического зодиакального знака Близнецов:


http://encyclopedia.astrologer.ru/cgi-bin/guard/Z/znaki_zod.html

Сведения взяты из рецензию на книгу:

"Nonlinear dynamics in physiology and medicine", A. Beuter, L. Glass, M. C. Mackey, and M. S. Titcombe (Editors), Interdisciplinary Applied Mathematics, vol. 25, Springer-Verlag, New York, 2003, xxvi+434 pp., $69.95, ISBN 0-387-00449-1

Рецензия помещена в математическом журнале:

BULLETIN (New Series) OF THE AMERICAN MATHEMATICAL SOCIETY
Volume 41, Number 4, June 17, 2004

http://www.ams.org/bull/2004-41-04/S0273-0979-04-01028-6/S0273-0979-04-01028-6.pdf