How Not to Be Wrong: The Power of Mathematical Thinking

by Jordan Ellenberg

Each one of these little local uncertainties percolated through the simulation, and the uncertainties about different parameters of the model fed back into each other, and by 2050, the noise had engulfed the signal. I could make the simulation come out any which way. Maybe there was going to be no such thing as tuberculosis in 2050, or maybe most of the world’s population would be infected. I had no principled way to choose. This was not what the researcher wanted to hear. It was not what he was paying me for. He was paying me for a number, and he patiently repeated his request for one. I know there’s uncertainty, he said, that’s how medical research is, I get that, just give me your best guess. It didn’t matter how much I protested that any single guess would be worse than no guess at all. He insisted. And he was my boss, and eventually I gave in. I have no doubt he told many people, afterward, that X million people were going to have tuberculosis in the year 2050. And I’ll bet if anyone asked him how he knew this, he would say, I hired a guy who did the math.