One of the key measurements of a galaxy’s shape is its ellipticity, which, for those who remember their geometry, is zero for a perfect circle and approaches one for something flat like a pancake. In the case of a galaxy, its ellipticity is a measure of how round it appears to us as we view it through a telescope. One might guess that, for an array of galaxies, the average of all galaxies’ ellipticities would be zero over a large volume, because galaxies are seemingly randomly oriented. That is, it would look as if a galaxy is just as likely to be slanted in one direction as any other. To the naked eye, this generally seems to be true. However, this is not quite the case!

In the early summer of 1945, physicist Bob Christy asked fellow physicist Richard Feynman to carry out a task as quickly as possible. The deadline was the Trinity nuclear test, the first nuclear bomb and the culmination of years of secret work by Manhattan Project scientists. The task was to predict the total energy that would be released by the Gadget device, the prototype implosion bomb designed at Los Alamos.