I have an upcoming talk in on data science. Now a ways such topics have been hijacked by talks on the use of machine learning. Deviating from the trend, I want to focus of core advancement of mathematics that has been made in times of crisis, especially war. Some examples - Linear programming was born out of the need of solving military logistics during the world war, Lagrange wrote treatise on ballistics to aid the Napoleonic wars
I am looking for examples from history and literature on
- Mathematics evolving out of military need
- Mathematics not specifically invented for military needs but found unexpected applications in military.
Please exclude general topics which are too board. E.g. calculus and trigonometry would not qualify because they are too board. Specific applications would also be interesting to look at e.g. the Jeep Problem