Sir Alan Hugh Cook FRS[1] (2 December 1922 – 23 July 2004) was an English physicist who specialised in geophysics and metrology.
He was the eldest of the six children of Reginald Thomas Cook, a customs and excise officer, and his wife, Ethel, née Saxon.
[2] After the war he returned to Cambridge to study for a doctor of philosophy (PhD) degree under the supervision of Edward Bullard and B. C. Browne.
[citation needed] Cook developed research interests in precision measurement across the physical sciences.
[3] Cook performed experiments including: determining the precise density of mercury, required for atmospheric pressure measurements (see mmHg); measuring the absolute acceleration of falling bodies (gravimetry); and determining the Earth's gravitational potential, by using the precisely known orbits of the Sputnik satellites (satellite geodesy).
He also contributed to precision measurements of time and length standards, particularly using hyperfine lines in the spectrum of cadmium and interference spectroscopy, laser interferometry and masers.