Dirac’s Model Airplane

In response to:

Silent Quantum Genius from the February 25, 2010 issue

To the Editors:

May I partially correct the caption accompanying the photograph of Paul Dirac [Freeman Dyson, “Silent Quantum Genius,” NYR, February 25]? It is not, as stated, “part of a model airplane” the famous physicist is holding but a complete craft. I know because I built several such planes myself (by coincidence in the same UK county, Essex, in which the photo was taken) as a schoolboy in the 1950s and though they were crude they were airworthy. The thin black line running the length of the upper fuselage (if a strip of balsa wood can be so characterized) is the motor: a length of rubber that when wound up and released powered the propeller that Dirac can be seen holding in his fingers to prevent it unwinding before he launched the thing.

Malcolm Gluck
London, England

Freeman Dyson replies:

Malcolm Gluck is correct. After he called it to my attention, I remembered that I flew a similar airplane when I was a child. I believe it arrived in a Kellogg cereal box. It only took a few seconds to assemble the wings and tail, then a minute or two to wind up the rubber. It flew remarkably well. I take this picture to be additional evidence that Dirac was not autistic.