Managing that uncertainty — quantifying it, propagating it through the calculation, designing systems that perform adequately across the range of conditions they will actually encounter — is the core technical challenge.

It is a challenge that requires not just mathematical skill but mathematical judgment: the ability to understand which uncertainties matter and which do not, which approximations are safe and which will cause problems, which simplifications are acceptable and which will produce results that the physical reality will contradict.

Mary Ross’s background in statistics — the work she had done before joining Lockheed, the statistical analysis she had contributed to in the 1930s — was directly relevant to this challenge.

Statistics and probability are the mathematical frameworks for managing uncertainty, for thinking rigorously about what you know and what you do not know, for quantifying the range of possible outcomes rather than pretending that a single expected value is sufficient.