In the early 1950s, David Sayre suggested
that the phase problem could be more easily
solved if you had at least one more intensity
measurement beyond those of the Bragg
peaks (Milestone 3) in each dimension. This
idea was inspired by Claude Shannon’s work
on communication theory and is a concept
understood today as oversampling.
William Lawrence Bragg and Max Perutz,
building on earlier work examining the
dehydration of haemoglobin crystals, came to
similar, but perhaps less precise, conclusions
using Fourier analysis.