Muriel Bristol knew that tea tasted better when the milk was poured in first, than when it was poured in after the tea. She knew it but couldn’t prove it and didn’t know why it was true. The world is better when more of us, more often, can act on what we know, but what we can neither prove nor explain. Too often regulations restrict the actions of entrepreneurs to what they can prove and explain, e.g., in the firing of employees.
This slows and reduces efficiency and innovation (not to mention freedom).
(p. C8) [Adam] Kucharski, a mathematically trained epidemiologist, says that the rigor and purity of mathematics has imbued it with extraordinary rhetorical power. “In an uncertain world, it is reassuring to think there is at least one field that can provide definitive answers,” he writes. Yet he adds that certainty can sometimes be an illusion. “Even mathematical notions of proof” are “not always as robust and politics-free as they might seem.”
. . .
. . ., proving what is “obvious and simple” isn’t always easy. Kucharski offers the delightful example of Muriel Bristol, a scientist who always put the milk in her cup before pouring her tea, because she insisted it tasted better. In the 1920s, a skeptical statistician designed a blind taste test to see if Bristol could distinguish between cups of milk-then-tea and cups of tea-then-milk. Bristol got all of them right. In 2008, the Royal Society of Chemistry reported that when milk is poured into hot tea, “individual drops separate from the bulk of the milk” and allow “significant denaturation to occur.” The result is a burnt flavor. Eighty years after Bristol was statistically vindicated, she was chemically vindicated too.
For the full review see:
(Note: ellipses, and bracketed name, added.)
(Note: the online version of the review has the date April 30, 2025, and has the title “Just Because You Can Prove It Doesn’t Make It True.”)
The book under review is:
Kucharski, Adam. Proof: The Art and Science of Certainty. New York: Basic Books, 2025.