TO HONOUR the physicist Enrico Fermi—father of the sustained nuclear
chain reaction—the US government has unwittingly repeated one of his rare
mistakes thousands of times and distributed it across the nation.
The United States Postal Service issued a stamp to commemorate Fermi on 29
September, the centenary of his birth. The stamp shows a photo of Fermi, who
died in 1954, standing in front of a blackboard on which he has fluffed the
equation for the “fine-structure constant”, a number that determines the
strength of electric and magnetic forces.
Denoted &agr;, the fine-structure constant combines the charge of the electron,…
