Uncle Abe had in his house a “spinthariscope,” just like the ones advertised on the cover of Marie Curie’s thesis. It was a beautifully simple instrument, consisting of a fluorescent screen and a magnifying eyepiece, and inside, an infinitesimal speck of radium. Looking through the eyepiece, one could see dozens of scintillations a second—when Uncle Abe handed me this, and I held it up to my eye, I found the spectacle enchanting, magical, like looking at an endless display of meteors or shooting
